Best Communication - Email - Mail Delivery Agents software in 2026

3 tools compared across pricing, features, and deployment.

Cyrus IMAP

cyrusimap.org

Open source

Email (IMAP/POP3), contacts and calendar server.

Communication - Email - Mail Delivery AgentsFree

DavMail

davmail.sourceforge.net

Open source

- POP/IMAP/SMTP/Caldav/Carddav/LDAP exchange gateway allowing users to use any mail/calendar client with an Exchange server, even from the internet or behind a firewall through Outlook Web Access.

Communication - Email - Mail Delivery AgentsFree

Dovecot

dovecot.org

Open source

IMAP and POP3 server written primarily with security in mind.

Communication - Email - Mail Delivery AgentsFree