efa-project.org

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 ?

This is doable.

You will need to simply edit the transport file directly and then issue the following command.

i.e

Yes, but this will be overwritten by EFA-Configure I suppose ?

Hmm...not sure....

Nope

I tried but not work, i suppose that reject_unverified_recipient uses VRFY instead RCPT TO and Exchange 2016 doesnt have VRFY

any solution to this problem yet?