On 26.08.21 15:36, post...@ptld.com wrote:
So I watched the sending server more closely in verbose mode and now I see it, I understand. For some reason sendmail is trying to send the same message twice, once with and once without a From: address. I also saw that sendmail ignores the rcpt reject and continues with the data command. Bad bot.
First tries to send message from non-existing (envelope) sender u...@example.com to non-existing (envelope) recipient u...@example.com Then (after the mail gets rejected) sendmail tries to send bounce to non-existing recipient (sender of the frst message) u...@example.com. The bounce gets rejected too. When you changed smtpd_reject_unlisted_sender to no, the only difference is that in the first message was rejected because of non-existing sender, later it's refused because of the non-existing recipient. Since the sender is the same as recipient (quote common in spam), the bounce was supposed to land on your server too. Good that you rejected it.
And thanks for the initial issue of figuring out I had smtpd_reject_unlisted_sender incorrectly set. Im done with this issue.
incorrectly? Unless you tend to send mail from non-existing addresses, I recommend you setting smtpd_reject_unlisted_sender=yes. This way you won't need to help with bounces to non-existing addresses. -- Matus UHLAR - fantomas, uh...@fantomas.sk ; http://www.fantomas.sk/ Warning: I wish NOT to receive e-mail advertising to this address. Varovanie: na tuto adresu chcem NEDOSTAVAT akukolvek reklamnu postu. - Have you got anything without Spam in it? - Well, there's Spam egg sausage and Spam, that's not got much Spam in it.
