SDP - Problem connecting to mailbox

SDP - Problem connecting to mailbox

Dear Support Team,

Still fighting with a common problem mail fetching from Exchange 2013.
Tried everything, all the protocol, ports, enabled/restarted services.

Everytime I get FAILURE :E-mail settings saved successfully. But error occurred while trying to check connection with mail server - Problem connecting to mailbox.

Please assist.

                  New to ADSelfService Plus?