I was wondering how I can change sendmails behavior with respect to handling rejection.
For instance sometimes my servers mail gets rejected by yahoo (and others) due to "spam" or other reasons. Instead of having those messages immediately returned to sender with a rejection notice I would like the messages to be queued for rescanning and perhaps for redirecting to be sent out through another non blocked mail server.
Here is an example
Feb 9 19:25:58 ob1 sendmail: m1A3Pp4W031084: to=<firstname.lastname@example.org>, delay=00:00:07, xdelay=00:00:00, mailer=esmtp, pri=129858, relay=mx1.comcast.net. [126.96.36.199], dsn=5.0.0, stat=Service unavailable
Feb 9 19:25:58 ob1 sendmail: m1A3Pp4W031084: m1A3Pw4W031097: DSN: Service unavailable
This message was bounced by comcast because the server was temporarily blacklisted with a message to the sender notifying them of the same. I would like to change sendmails default response to dsn=5.0.0 errors so that the message is not immediately returned to sender but queued for rescanning and submission through a non blocked mailler.
Apologies if there is an obvious answer to this. I have searched high and low for about two weeks.