CiviCRM Community Forums (archive)

I sent a CiviMail recently using sendmail and was suprised to see bounce statistics being recorded.  I was under the impression that to get bounce info, you needed to use SMTP and configure some mailbox checking of a bounce inbox.

No, if the ‘bounce’ is caused by the email (most often – its headers) being malformed¹, then it registers right away. In such cases the Mail PEAR library (which we use as a nice common wrapper for both SMTP and sendmail) returns an error, and we treat it like a bounce. I could also imagine some sendmail errors making the Mail library report an error back to us (and, of course, ‘hard’ SMTP bounces – i.e., ones during the initial attempt to send the email – should be registered outright).

¹ or you’re using CiviCRM 3.0.3 or 3.1.2, which had some infamous CiviMail bugs, or you’re mailing a contact with no name, just an email address – this, in turn, will be fixed in 3.0.5/3.1.4…