Hi Agent86,
If you are refering to your users email on sme then Thunderbird can be used to collect the emails, just use mail.yourdomain.xxx or yourserverip for the pop3 and smtp server settings and the normal user name and password for the account. This only works within the local network unless you change the pop3 setting in server manager from "Allow private" to "Allow private and public (secure POP3S)" I hope this helps.
Regards,
Del