Recipient Verification problem
Posted: 05 Sep 2016 08:59
For users that have EFA between Exchange and Internet is very useful to enable postfix recipient verification
reject_unknown_recipient_domain, check_recipient_access hash:/etc/postfix/recipient_access, reject_unverified_recipient, check_policy_service inet:127.0.0.1:2501
When reject_unverified_recipient enabled postfix check Internal server making a RCPT TO while external server make RCPT TO to postfix and answer USER UNKNOWN if internal server answer so.
With Exchange 2016/2013 there is a problem, the FrontEnd connector doenst do this check, and bounce later
Solution is to enable Exchange "Recipient Filter Agent"
With "Recipient Filter Agent" we have
Hub Transport that receive at port 2525 that check mailbox exixstence at RCPT TO level
Frontend Transport that receive at port 25 that check mailbox exixstence at DATA level
Obviously postfix doesnt simulate at data level but only at rcpt to level
So we need to create an Hub Transport on port 2525 and we need that EFA in /etc/postfix/transport specify port 2525
is possible ?
reject_unknown_recipient_domain, check_recipient_access hash:/etc/postfix/recipient_access, reject_unverified_recipient, check_policy_service inet:127.0.0.1:2501
When reject_unverified_recipient enabled postfix check Internal server making a RCPT TO while external server make RCPT TO to postfix and answer USER UNKNOWN if internal server answer so.
With Exchange 2016/2013 there is a problem, the FrontEnd connector doenst do this check, and bounce later
Solution is to enable Exchange "Recipient Filter Agent"
With "Recipient Filter Agent" we have
Hub Transport that receive at port 2525 that check mailbox exixstence at RCPT TO level
Frontend Transport that receive at port 25 that check mailbox exixstence at DATA level
Obviously postfix doesnt simulate at data level but only at rcpt to level
So we need to create an Hub Transport on port 2525 and we need that EFA in /etc/postfix/transport specify port 2525
is possible ?