It is extremely easy to set up an IMAP server with SSL. On Red Hat EL5 (or CentOS5) it is a two-step process. You can optionally get a Thawte or UW-CA cert and put it at /etc/pki/tls/certs/localhost.crt if you don't want to use a self-signed one. It's a simple IMAP setup but probably an option for dept archives. Works with Alpine, Thunderbird, Apple Mail, and Outlook.

1. Install dovecot

yum -y install dovecot

2. Here is the entire /etc/dovecot.conf file to use:

auth_verbose = yes
verbose_ssl = yes
mail_location = maildir:~/Maildir
protocols = imaps

protocol imap {
}

auth default {
  mechanisms = plain
  passdb pam {
  }
  userdb passwd {
  }
  user = root
}