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User Guide - Email User Guide

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Applicable Plans: All Standard VPS, All Advanced VPS, all Premier VPS plans

E-mail User Guide

The eApps Control Panel provides a powerful interface for managing your e-mail accounts and services. You can set up mail boxes, mail forwarding, catch-all accounts, mailing lists, and auto-responses all within your Control Panel.

Note that all domains that use eApps DNS are now configured to use the SpamExperts Spam and Anti-virus service by default. See the SpamExperts User Guide for more information.

Overview of your Mail Service 

Installing Mail Services 

Spam Filtering Tools

Mailboxes and Mail Forwarding 

Configuring your E-mail Client Software 

Mail Server Configuration 

Links to other information


Overview of your Mail Service

All eApps VPS hosting plans include their own mail server, running sendmail, which is the most popular MTA (Mail Transfer Agent, also known as a Mail Server) on the Internet. This differs from most other hosting services in that the mail server for your VPS only handles e-mail for the sites and domains on your VPS. Many hosting services use a shared mail server for all customers, which can easily be blacklisted by the major spam filtering services if another hosting customer is sending spam or abusing the service. Also, a shared mail server can incur performance issues if another customer is sending or receiving a high volume of e-mail. With your own separate mail server, you are not impacted by the activities of other customers.

Installing Mail Services

Services/applications installed by default

Sendmail is included as part of the standard installation of your VPS. Also included are the UW IMAP server and POP3 server. Because they are part of the standard installation, these servers/services do not need to be installed. They also cannot be uninstalled from your VPS, because certain system events will cause the Control Panel software to re-install them and set them as the default applications for mail services.

If you wish to use a different mail server/IMAP/POP3 service, you will have stop the installed services and configure them to not start again when the VPS is restarted instead of uninstalling them. Since eApps only supports the applications as installed from the Control Panel, we offer no instructions on how to disable these services. If this is the route you are taking, it is assumed you are an expert in Linux and Linux mail servers and will be able to find this information yourself.

Applicatons that can be installed

The following are e-mail related applications that can be installed from the Control Panel. Not all applications are available in all Plans, see the table below for more information.

*On CentOS 4 plans, either Majordomo OR Mailman could be installed. On CentOS 5 plans, both Majordomo AND Mailman can be installed.
  CentOS 4 CentOS 5
Open Webmail
Majordomo w/ Autoresponder*

To see what operating system (OS) you have, click on the Subscriptions icon from the My Account tab of your Control Panel. Then click on the name of the subscription you want to see. The OS for the subscription will be displayed near the top of the page

How to install applications

Login to your Control Panel, and click on the System Tab. If necessary, click the Select Another System (Subscription) link on the left and choose the correct Virtuozzo Container system.

Go to Applications, and click on the Add Application link. Select the box next to the application that you wish to install, and then scroll down and click the Next button.

This takes you back to the All Applications screen. Wait for five minutes, then click on the Refresh link at the upper right, just under the word Parallels. The application should now show as installed. If it is still in a Scheduled state, wait another five minutes, and click Refresh again. If you see it in Error state, or it still shows as Scheduled, please contact eApps Technical Support.

Application Overview

RoundCube Webmail – (CentOS 4 only) This webmail application is implemented with AJAX. It has an easy to use interface and supports IMAP. More information can be found at Roundcube is no longer being supported for customers using the CentOS 5 operating system and later, primarily because the open source project is not very active and the application consumes a lot of resources. If installed, Roundcube is accessed from (substitute your domain for

SquirrelMail Webmail – (CentOS 5 only)This is a mature, reliable and easy to use webmail application, implemented with PHP. It provides IMAP support and is extremely browser friendly, requiring no client side scripting to run. More information about SquirrelMail can be found at If installed SquirrelMail is accessed from (substitute your domain for

Open Webmail – (CentOS 4 and 5) Open Webmail is a reliable webmail application used by many eApps customers because of its ease of use and small resource footprint. One important feature of OpenWebMail is that it allows users to change their password. More information about this application can be found at If installed, Open Webmail is accessed from (substitute your domain for

Majordomo with Auto-Responder – (CentOS 4 and 5) Majordomo is a mailing list application that also provides auto-responder functionality for mail boxes. This application is integrated with the Control Panel, making it easy to use. The Majordomo User Guide has more information on setting up and using this application. In CentOS 4, either Majordomo OR Mailman could be installed, but not both. In CentOS 5, both can be installed. If installed, Majordomo is accessed from the Control Panel, System Tab, Mail Management. There will be a Mailing Lists link in this section.

Mailman – (CentOS 4 and 5) Mailman is a mailing list manager. It provides its own web interface for managing the mailing lists. Mailman is newer than Majordomo, and unlike Majordomo, is still currently being updated. The Mailman User Guide has information and instructions on setting up and using this application. Mailman requires more work on the front end to setup and configure, but is easier to use in the long run. In CentOS 4, either Majordomo OR Mailman could be installed, but not both. In CentOS 5, both can be installed. If installed, Mailman is accessed from the Control Panel, System Tab, Application Management, All Applications. Click on Mailman, and there will be a URL listed to access the default setup. Please read the User Guide first as there are some specifics to our Mailman application that you need to be aware of before starting to use the application.

Spam Filtering Tools


eApps uses the SpamExperts system for all mail traffic. More information can be found in the SpamExperts Admin Guide and SpamExperts User Guide

Legacy Spam Filtering Tools

The following are the older spam and anti-virus tools offered by eApps. If you are using SpamExperts, you do not need to install any of these applications. SpamExperts does a better job at spam and anti-virus filtering, and does all the work off your VPS, saving you valuable system resources. Please see the Fighting Junk mail User Guide for more information on these legacy applications.

SpamAssassin - This package, along with the smtp-vilter application, is used to mark spam received on the VPS and deliver that to your inbox. It is very resource intensive, and can cause a lot of resource problems on the smaller Standard plans. If you want more information about Spamassassin, it can be found at

ClamAV - ClamAV is an anti-virus application. Once installed it will scan incoming messages for virus threats. Unless you need to scan your file system for viruses ClamAV is not needed, and will consume a lot of memory and CPU power without adding any benefit.

Greylist Filter – Greylist filter works by rejecting the first message sent to you from an unknown sender. This causes the sender’s mail server to send the message again, usually after a delay ranging from a few minutes to a few hours. After that initial delay, the message and all other messages from this person are passed on to your inbox. This works because this behavior is standard among all RFC compliant mail servers. Spammers generally do not use compliant mail servers, and so their messages will not be sent again. While not 100% effective, Greylist is the best choice to install if you are not going to use SpamExperts. See the link to the Junk Mail guide above for more information on Greylist, as well as the Greylist User Guide.

Mailboxes and Mail Forwarding

There are two ways to receive e-mail on your VPS – mailboxes and mail forwarding. A mailbox is used when you want the mail server to retain messages for you to access using a standalone e-mail client such as Outlook, or Thunderbird or from a webmail application such as Open Webmail or Squirrelmail. Mail forwarding configures the mail server to receive the e-mail, and then immediately forward it to another e-mail account, either on your VPS or to an external mail server, such as Gmail or Yahoo.

Creating Mailboxes

To create or manage the mailboxes (not mail forwarding) on your VPS, log in to your Control Panel, and click on the System Tab. If necessary, click the Select Another System (Subscription) link on the left and choose the correct Virtuozzo Container system. Then, scroll down to Mail Management, and then Mailboxes. This is where you can add mailboxes or manage existing mailboxes.

To create a new mailbox, click on Add Mailbox.

The first part of the E-mail field is the user’ part of the e-mail address. The user name has to be in lower case letters, can use the digits 0 – 9 and can only be a maximum of 40 characters. There are ways around the 40 character limit, but they are non-trivial to implement. If you really need to have an e-mail address where the user name is over 40 characters, please contact eApps Support.

The second part of the E-mail field is the @domain part of the e-mail address. This is a drop down menu where you can choose any domain that exists on your VPS, or set the user up as an @(multiple domains) user.

There are differences between the two approaches, which are discussed below. One main difference is that a ‘user@(multiple domains)’ e-mail account creates an actual system user, with a /home/username directory and an entry in /etc/passwd, while a ‘user@specific domain’ e-mail account creates a virtual user with no actual home directory and no /etc/passwd entry.

The preferred way to set up an e-mail account is the ‘user@(multiple domains)’ approach. However, if you will have a lot of e-mail users, the main limitation to the ‘user@(multiple domains)’ approach is that there can only be one account of a particular name. In other words, if you have a ‘sue@(multiple domains)’, that is the only ‘sue’ e-mail user you can have. With a ‘user@specific domain' approach, you can have ‘’, and ‘’, and ‘’, all of whom can be different people/users.

user@(multiple domains)

  • Can receive e-mail for any domain on the VPS as,, etc
  • Can use SMTP Authentication instead of POP before SMTP Authentication (SMTP Authentication is necessary to use Domain keys)
  • Can have mail forwarding setup where a copy of the e-mail is left on the VPS and also forwarded to another account

The inbox for a ‘user@multiple domains)’ e-mail user is located at /var/spool/mail/username

user@specific domain

  • Can only receive e-mail for their specific domain
  • Can only use POP before SMTP authentication
  • Can set up mail forwarding, but no copy of the e-mail is left in their account on the VPS.

The inbox for a ‘user@specific domain’ e-mail user is located at /var/spool/vmail/

Once you have decided on the approach you will use for the e-mail address, you can then set the password for this mailbox. You will be forced into setting a difficult password, and this feature cannot be changed or altered. This is for your protection.. Retype the password to verify.

If you have Majordomo with Autoresponder installed, you can configure your Autoresponder here. If not, or if you do not want to configure the Autoresponder at this time, just click Finish. This creates the inbox on the VPS, and adds the e-mail user to the Control Panel.

Please note – eApps Support will never know what your password is. The passwords are encrypted in the Control Panel database, and we cannot recover them or see them. If we have to ask you for your password, what we will usually do is ask you to login to the Control Panel, and put your password in the Description field for the mailbox. That keeps you from having to send your password to us in an unencrypted format in an e-mail or ticket.

To manage an existing mailbox, simply click on the mailbox itself. There you can change the password, and if the Autoresponder program is installed, you can turn it off or on and change the Autoresponder message.

To delete an existing mailbox, click on the red X to the far right of the mailbox name in the Maiboxes section of the Control Panel. Note that deleting the mailbox also deletes any e-mail currently stored in that inbox.

Setting up Mail Forwarding

To create or manage the mail forwarding on your VPS, log in to your Control Panel, and click on the System Tab. If necessary, click the Select Another System (Subscription) link on the left and choose the correct Virtuozzo Container system. Then, scroll down to Mail Management, and then Mail Forwarding. This is where you can add mail forwarding rules or manage existing mail forwarding rules.

To create a new forwarding rule, click on Add Forwarding Rule.

In the E-mail field, enter either an e-mail user that already exists on the VPS in the Mailboxes section, or specify a new user (this new user will only exist as a mail forward). 

Then choose the domain to match the e-mail user from the drop down menu, or if you are creating a new user that will only exist as a mail forward, choose the appropriate domain from the drop down menu.

In the Forward to (a) local mailbox(es) section, choose a mailbox or mailboxes on the VPS to forward this e-mail to. Note – you cannot choose the same e-mail address as the mail forward you are trying to create. This will result in this error message when you try to click Save: You tried to set up a mail forward that creates a mail loop. This action is not allowed. Only a ‘user@(multiple domains)’ e-mail user can be set up to have mail both forwarded and left in their inbox, and that requires manual changes to the VPS from the command line. See below for more information on this.

In the Forward to (an) external mailbox(es) - use comma separation to add multiple addresses section, you can specify e-mail addresses for users and domains that do not exist on your VPS, such as or, separated by commas. There is no limit to how many forwards can be set here.

In a Mail Forward, you can have mail forwarded to both local and external mailboxes.

Once you have set up all your mail forwards for this e-mail address, click Save. This creates the new Mail Forward in the Control Panel.

To manage an existing mail forward, simply click on the forward itself, and you can change the forwarding addresses, adding or removing as needed.

To delete an existing mail forward, click on the red X to the far right of the mail forward in the Mail Forwarding section of the Control Panel.

How Mail Forwarding works

For a standard mail forward, the mail server processes the forwarding rule before any other operations are performed on the e-mail. This means that by default, the mail forwarding takes place immediately, and the e-mail is forwarded to the e-mail addresses specified in the forwarding rule, and no copy of the e-mail is kept in the original inbox. If the mail forward points to an external e-mail address off the VPS, then no copy of the e-mail is even kept on the VPS, it is simply forwarded to the other e-mail address.

A ‘user@(multiple domains)’ e-mail user is able to have e-mail both forwarded and left in the original inbox, but this requires manual configuration from the command line of the VPS. If you need information on how to accomplish this, please send a support ticket to with your domain name and the reason for the request, and we will send you instructions on how to set this up. These instructions will assume you are able to connect to your VPS as the root user via SSH, and can edit files on the command line with the vi editor. If you are not able to do this yourself, we will set up one forward for you, but setting up multiple forwards will be considered a billable request at our standard rate of $15 per 10 minutes.

Configuring your E-mail Client Software

Depending on how you count them and where you look, there are dozens, if not hundreds, of e-mail clients available. Wikipedia has a large list, another list is here. For this User Guide, an e-mail client is defined as a stand-alone program that you have installed on your own computer, not one of the webmail clients offered by eApps.

Because of the large number of e-mail clients available, it is not possible for eApps to offer support for any e-mail client beyond the most basic configuration questions.

While we will make every effort to assist you with setting up your e-mail client, you are ultimately responsible for resolving any issues with the installation, configuration and usage of your e-mail client software. For advanced configuration or usage questions, you may need to contact vendor support for your e-mail client or consult some of the many resources online for more information.

Our support is limited to the mail server itself. If our testing shows that the mail server is accepting e-mail and sending e-mail, then that is essentially the end of our responsibility. Again, we will assist you as best we can with your e-mail client configuration issues, but may have to refer you to the software vendor for more assistance if necessary.

There are currently User Guides available for Microsoft Outlook, Microsoft Outlook Express and Thunderbird that should be of assistance if you are using one of those e-mail clients.

General E-mail Client Configuration Settings

No matter which e-mail client you use, you will need to configure it with the same general settings in order to send and receive e-mail. Where these settings are located will depend on your e-mail client, so please consult the official documentation for your e-mail client if you are not sure where these settings are located or how to change them.

NOTE – all of these settings assume that you are using your VPS at eApps to send and receive e-mail. If you are not using your eApps VPS as your mail server, please consult your local network technician or system administrator for more information.

  • Incoming Server Name (POP or IMAP) – whether you are using POP3 or IMAP, your incoming mail server will be your fully qualified domain name, in the form of (substitute with your actual domain name). Usually will also work, but if that doesn’t work, try just
  • Incoming Server Port (POP or IMAP) – by default, the incoming server port for POP3 is port 110, and the incoming server port for IMAP is port 143. It is possible to set up your mail server to use POP3 and IMAP on their secure ports with SSL/TLS, but that requires you to make manual changes to the sendmail configuration files from the command line of your VPS. See the Securing Email with SSL/TLS User Guide for more information.
  • Outgoing Server Name (SMTP) – the outgoing SMTP server name is the same as the incoming POP or IMAP server name, which is your fully qualified domain name, in the form of (substitute with your actual domain name). Usually will also work, but if that doesn’t work, try just
  • Outgoing Server Port (SMTP) – by default, the outgoing SMTP port is port 25. It is possible to set up your mail server to use SMTP on the secure port with SSL/TLS, but that requires you to make manual changes to the sendmail configuration files from the command line of the VPS. See the Securing Email with SSL/TLS User Guide for more information.
If you are unable to connect to port 25 on your VPS, your ISP or local network may be blocking outbound connections to port 25. Many ISPs do this in an attempt to block spammers from using their customer’s computers to send spam. If you think that port 25 is being blocked, see the Mail Server Configuration – General Mail Server troubleshooting section of this User Guide for more information.


  • E-mail address – your e-mail address is the e-mail address you are using to send and receive e-mail from for this account. For a ‘user@(multiple domains)’ e-mail user, use the main domain that you will be sending e-mail from.
  • User Name – the User Name will depend on how your e-mail account was created. If the e-mail account was created as ‘user@(multiple domains)’, then the User Name will be the ‘user’ part of the e-mail address. If the e-mail account was created as ‘user@specific domain’ then the User Name will be the full e-mail address.
  • Passwords  – all e-mail clients will have a place for you to put your password. Make certain to enter the password exactly as it was given to you. If possible, manually type the password in, instead of using copy and paste, which can insert spaces at the beginning and end of the password if you are not careful. Check the ‘Remember Password’ box if available.
  • Authentication – Unless you have made the manual changes to your VPS for the SSL/TLS or SMTP Authentication, make sure to uncheck any settings about requiring authentication or secure connections. Some e-mail clients have these settings checked by default, and this is the cause of quite a few support tickets and calls. If you are getting errors from your e-mail client about not being able to establish a secure connection to the SMTP or POP server, double check these settings.

Mail Server Configuration

As installed, your mail server needs no additional configuration changes to work. However, there are some changes that can be made, depending on your requirements.

Mail Server Authentication Methods

The mail server can use POP before SMTP Authentication or SMTP Authentication, and SSL/TLS encryption for either authentication method.

POP before SMTP authentication

The mail server uses what is called POP before SMTP authentication as the default authentication method. No changes to the mail server have to be made to use POP before SMTP authentication.

POP before SMTP authentication means that you have to first check your e-mail (POP or IMAP) before you can send your e-mail (SMTP). Please note that your mail server IS NOT an open relay. The SMTP server will not send any outgoing e-mail unless the user trying to send e-mail has established an valid POP connection, which requires a user name and password.

SMTP Authentication

The mail server authentication can be changed to also use SMTP Authentication, also called SMTP AUTH, instead of POP before SMTP authentication if your needs require this. Only a ‘user@(multiple domains)’ e-mail user can use SMTP Authentication. A ‘user@specific domains’ e-mail user cannot use SMTP Authentication, those users will still use POP before SMTP authentication.

To set up SMTP Authentication, you will need to login to the command line of the VPS via SSH as the root user. See the SSH User Guide for more details on this.

Once logged in, follow these steps to set up SMTP Authentication. What has to be done is to copy the smtp.sendmail file in /etc/pam.d to a file called smtp. There will be a symbolic link for an smtp file already in place, pointing to /etc/alternatives/mta-pam. This link will be removed so that the SMTP Authentication will work.

[root@example ~]# cd /etc/pam.d/
[root@example pam.d]# ll smtp
lrwxrwxrwx 1 root root 25 Jun 26 21:57 smtp -> /etc/alternatives/mta-pam

[root@example pam.d]# rm -rf smtp
[root@example pam.d]# cp smtp.sendmail smtp

[root@example pam.d]# ll smtp
-rw-r--r-- 1 root root 72 Jun 26 21:59 smtp

Once this change has been made, any ‘user@(multiple domains)’ e-mail user should be able to use SMTP Authentication to connect to the mail server.

SSL/TLS Encryption

The mail server can be changed to allow SSL/TLS encryption to connect. Please see the SSL/TLS User Guide for more information. Both the POP before SMTP and SMTP Authentication approaches can use SSL/TLS encryption.

General Mail Server troubleshooting

Due to the complexities and intricacies of  sendmail , it is impossible to provide a comprehensive troubleshooting guide. For example, the standard reference to sendmail, available from O’Reilly, is 1300 pages long, and the main sendmail configuration file ( over 1800 lines long and requires its own macro language in order to edit the file.

However, there are a few things you can try to troubleshoot various mail server  problems. Two of the most common problems we encounter are issues with Spamassassin and smtp-vilter, and port 25 being blocked by an ISP or local network.

If you have any questions or problems with these troubleshooting steps, please contact eApps support for more assistance.

Spamassassin and smtp-vilter – if you are having trouble sending or receiving e-mail, and you have Spamassassin and smtp-vilter installed, please remove them if you are using SpamExperts. Spamassassin is very resource intensive, and if the program gets into an error state due to resource problems it will stop your e-mail from working.

To remove Spamassassin and smtp-vilter, log in to your Control Panel, and click on the System Tab. If necessary, click the Select Another System (Subscription) link on the left and choose the correct Virtuozzo Container system. From there, go to All Applications. Starting with Spamassassin, click on the link for the application, and click Uninstall. You may be shown a warning screen saying that it is not completely safe to uninstall this application. Click OK and continue.  This will take you back to the main All Applications screen. Wait about five minutes, then click on the link to smtp-vilter, and uninstall it also. If these applications were causing your problem, you mail should start working again fairly quickly after removing both applications. If you are still having problems, please contact eApps support.

Port 25 blocked – many ISPs now block outbound connections on port 25 to any mail server that is not their own mail server. This is primarily done to prevent hijacked PCs on their network from bypassing their internal spam controls when sending e-mails. 

If you are able to receive e-mails, but not send e-mails, then your issue may be that port 25 is blocked. It is possible to open another SMTP port on the mail server. If you are not comfortable making this kind of change, please contact eApps support for assistance.

To test if port 25 is being blocked, you will need to telnet to the mail server on port 25 and see if you receive a response. To do this, you will need to get to a command prompt on your operating system.

If you are on Windows XP, bring up the command prompt by going to Start > Run – then type cmd in the Run box. This brings up the command prompt.

 On Windows Vista, you will first have to enable telnet. See this link for more details. Once telnet is enabled, go to Start > All Programs > Accessories > Command Prompt.

 If you are on Windows 95 or 98, please consider upgrading as soon as possible. The command prompt on Windows 95/98 can be found in a similar manner to Windows XP, though on some older versions of Windows you may have to use command instead of cmd.

For Mac OS X, you will need to use the Terminal application. Go to Applications > Utilities – Terminal . Make sure you are using Terminal, and not Console.

For Linux/UNIX/*BSD bring up your terminal client of choice.

Once the command line is open, follow these steps. Remember to replace ‘’ with your actual domain name.

telnet 25 <press return or enter>
Connected to
Escape character is '^]'.
220 ESMTP Sendmail 8.14.3/8.14.3; Fri, 26 Jun 2009 23:28:15 -0400

If your connection goes all the way to the 220 response from the mail server, your outbound connection to port 25 is open, and there should be no physical reason for you not to be able to send mail.

If your connection stops at the Trying (this will be the IP address of your VPS) line, and either never connects or eventually returns an error message, then either your ISP or local network blocks outbound connections to port 25. If this is the case, you can contact eApps support to discuss having port 587 opened, or contact your ISP or network administrator and ask them to unblock that port for you. Some ISPs only block ports on their ‘residential’ plans, so you may be able to upgrade to a higher plan to have this port unblocked. Contact your ISP to discuss this, though.

Relaying Denied/ No Relaying Allowed Errors

Another common problem with trying to send e-mail is a Relaying Denied or a No Relaying Allowed error. Although the error messages look similar, they have different resolutions.

Relaying Denied – this error occurs when your e-mail client has lost authentication to the mail server. Once the authentication is lost, your mail server thinks that you are trying to send the e-mail AS the person you are trying to send TO. The fix for this is two-fold. First, close your e-mail client, then reopen it, and then check your e-mail and then try to send your e-mail. This re-authenticates you to the mail server, so your e-mails should send without any issues. The second thing to do is lower the mail check interval in your e-mail client software, changing it to around 2 minutes. This will keep your e-mail session authenticated.

No Relaying Allowed – this error is usually seen when trying to send an e-mail to a new e-mail address on the VPS. The key phrase to look for in this error is “smtp”. This means that SpamExperts does not yet have the domain or e-mail address added yet. If you have a SpamExperts Admin account, you will need to add either the domain, the e-mail address, or both to SpamExperts. If you do not have SpamExperts Admin access, please contact eApps support for more assistance.

Links to other information

Sendmail official site –
Mail server testing tool –
E-mail Explained from -
Wikipedia entry on e-mail -
HowStuffWorks - How E-mail Works article -

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