How do I setup my server for POP3 mail?

First, the domain(s) which you are going to use for mail need to have MX records that point to your server. If you are using AceShellss name servers you can do this in the DNS manager. If you are using the domain(s) for mail and want a seamless changeover you should leave this step until last.
The software package we recommend for mail services is postfix, and you will also need a POP3 daemon; we recommend qpopper.

To install these you can use apt:

apt-get install postfix
apt-get install qpopper
Under RedHat you will need to install qpopper manually. If you are unsure how to do this, please see the section on installing RPM's, or contact support.

Postfix needs a couple of changes to its default configuration file before it will work. Edit /etc/postfix/main.cf and add / uncomment the following lines:

virtual_maps = hash:/etc/postfix/virtual

inet_interfaces = localhost, <your_ip_address_here>
Finally, you need to add the domain names and email addresses into /etc/postfix/virtual. The format is as follows:

yourdomain.com vitrual
fred@yourdomain.com fred
bloggs@yourdomain.com fred
simon@yourdomain.com simon@anotherdomain.com
@yourdomain.com john
This will make emails to bloggs@yourdomain.com or fred@yourdomain.com be delivered to the user "fred". The default mailbox location is /var/spool/mail/. Any other email sent to something@yourdomain.com will go to the user "john".

Whenever you make a change to the virual file Postfix's databases must be rebuild. This can be done by running the command below while in /etc/postfix:

postmap /etc/postfix/virtual
qpopper will automatically provide POP3 access to the default mailboxes using normal user validation.

How do I setup my server to act as a SMTP relay?

First, we cannot allow users to setup open relays. They are security risks and against our AUP.
We would recommend that you use POP3 pre-authentication. This works by getting the user to fetch their mail by POP3 first. The daemon then caches the user's IP address and will allow relaying for a limited time (30 mins by default).

The first setup is to setup postfix and qpopper as described above. If using Debain, then simply install the qpopper-dracd package:

apt-get install qpopper-dracd
Under Redhat one of the required packages for qpopper is "dracd". dracd (dynamic relay access control) is the software that does the authentication as described above. First install openssl libraries:

apt-get install openssl095a
Then install these RPM packages we have made available for download:

dracd-1.11
qpopper-4.0.1

wget http://www.AceShells.com/downloads/dracd-1.11-1.i386.rpm
wget http://www.AceShells.com/downloads/qpopper-4.0.1-1.i386.rpm
rpm -Uvh dracd-1.11-1.i386.rpm qpopper-4.0.1-1.i386.rpm

Note: dracd requires portmap which is somewhat insecure and should only be used if you have setup /etc/hosts.allow and /etc/hosts.deny, and preferably a firewall also. If you are unsure how to do this please contact support.
To start using POP3 pre-authentication you need to add/uncomment this line in /etc/postfix/main.cf:

Debian:
mynetworks = btree:/var/lib/drac/dracd

Redhat:
mynetworks = btree:/etc/mail/dracd
You should then just need to restart xinetd and postfix.

How do I setup an autoresponder?

We suggest using procmail for autoresponders and other automated mail processing. The first step is to turn on procmail handling in postfix. Edit /etc/postfix/main.cf and add/uncomment the following line:
mailbox_command = /usr/bin/procmail

Next create a .procmailrc file in the users home directory. You can use this as a template:

EMAIL=you@yourdomain.com
SHELL=/bin/sh

:0 Whc: vacation.lock
# Perform a quick check to see if the mail was addressed to us
* $^(To|Cc):.*$EMAIL
# Don't reply to daemons and mailinglists
* !^FROM_DAEMON
# Mail loops are evil
* $!^X-Loop: $EMAIL
| formail -rD 8192 vacation.cache

:0 ehc # if the name was not in the cache
| (formail -rI"Precedence: junk" -A"From: $EMAIL" -A"X-Loop: $EMAIL" ; \
cat $HOME/.autoreply; \
) | $SENDMAIL -oi -t

The final step is to write the message you want to be sent out as the auto response and put the body of that message in the file .autoreply in the users home directory.