efa-project.org

My E.F.A. accepts emails for non-existant users. When I have domain setup in the transport map and have users entered into Mailwatch it works fine for those users but it also receives emails for invalid users in that domain. The result is the emails get forwarded from E.F.A. to my regular mail server where they are rejected as invalid users and an attempt is made to return to sender, but the sender is usually invalid and so I have a backscatter problem.

Does Postfix have address_verification where it will not accept a new incoming email until it verifies the recipient is a valid email of the end mail server? I was reading up on that but not 100% sure I understand how it works.

Is there any way to stop backscatter by verifiying the recipients are actually valid?

Thanks!

After doing some more research I found the option I was looking for:

reject_unverified_recipient

This needs to be added after option

reject_unknown_recipient_domain

In Postfix main.cf section smtpd_recipient_restrictions

Now when an email comes in and the recipient is an invalid email address is gets rejected at E.F.A. and does not attempt to send it.

This link was helpful: http://blog.endpoint.com/2015/05/postfi ... ation.html

webguyz wrote:After doing some more research I found the option I was looking for:

reject_unverified_recipient

This needs to be added after option

reject_unknown_recipient_domain

In Postfix main.cf section smtpd_recipient_restrictions

Now when an email comes in and the recipient is an invalid email address is gets rejected at E.F.A. and does not attempt to send it.

This link was helpful: http://blog.endpoint.com/2015/05/postfi ... ation.html

Just installed this line, will check it out. Should be added to the default setup, to prevent backscatter i guess

I'm pretty sure my EFA doesn't backscatter and mine also accepts any incoming mails for domains it is responsible for. Did you change any settings related to this?