Additional Bounce Patterns according to SMTP status codes
Currently SMTP status codes are mostly ignored when processing and classifying mails for bounces. I wrote a stackexchange question to see if someone had already implemented this.
Since I got no feedback, I did it myself and had promising test results with the additional pattern:
From a sample bounce pool of approx. 4500 Mails, ~1500 were classified as syntax bounce (read: unknown) with the default bounce pattern. With the new pattern that shrank down to 400. (With some custom German away messages not yet parsed, so results should be even better, around ~200 syntax bounces)
My question would be if a pull request on civicrm-core is preferred, or if I should build an extension managing additional bounce pattern? I realize that with only 10 classifications available in CiviCRM-Bounce Type Vs. 30-50 SMTP Error codes the mapping could be open for some discussion, but I think this is a good start.