
1) Linux correspondence client 2) Unix correspondence software
Found on
https://www.crosswordclues.com/clue/xmail

XMail is a free open-source developed by Davide Libenzi, POP3/ESMTP mail server for Unix and Microsoft Windows operating systems. Unlike other email servers, XMail does not require that each user have a system account, instead it uses flat-file databases to store user information. XMail is a light-weight email server ideally suited for use in situ...
Found on
http://en.wikipedia.org/wiki/XMail
No exact match found.