Mail service in ISPmanager is provided over dovecot POP3 and Exim SMTP servers. This couple has been tested fully.
With ISPmanager you are able to:
create mail domains,
configure mail domains,
delete mail domains,
view and configure mailboxes, redirects and mail groups for specific mail domains.
All mail domains and mailboxes created in ISPmanager are virtual and do not require real users. Mail is stored in the Maildir format. SMTP authorization is performed with the help of sasldb2 or dovecot socket. Mail delivery and quotas are managed by dovecot.