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.
ISPmanager uses POP3 and IMAP protocols to receive emails. User disk quota includes the space occupied by a mailbox.
ISPmanager allows you to configure:
white and black lists,
Sieve mail sorting.
Also, you can create one address for several users, set up aliases for mailboxes, and configure mail forwarding.