c***@gmail.com
2018-10-18 12:11:53 UTC
Hello,
I've got a strange issue with a customer which has raised a couple of questions. The first isn't strictly Postfix related, although it's the cause of the second question and explains what's going on.
The disconnect log from one of their sessions looks like the following (74 separate emails sent) -
disconnect from unknown ehlo=1 auth=1 mail=148 rcpt=148 data=74 rset=75 quit=1 commands=448
Now the interesting thing to note is that it sends twice as many mail/rcpt commands as data, and 75 resets. This is because the client sends MAIL/RCPT/RSET once for each email, then does another RSET for good luck, then does a full MAIL/RCPT/DATA sequence for each email.
First question is has anyone seen anything like this? Client is apparently Outlook - and the emails do have a 'X-Mailer: Microsoft Outlook 14.0' header - so I'm generally ruling out my first thought of a dodgy client. I'm wondering if there's some sort of AV that could do this?
Anyway the second question is that in some cases, the log looks like this -
disconnect from unknown ehlo=1 auth=1 mail=120 rcpt=120 rset=120 commands=362
In this case it tried to send 120 emails, but on the 121st MAIL command, got kicked off with a 'too many errors' message. No errors are reported in the smtp connection, and nothing appears in the log other than the final "too many errors".
Can someone tell me what error Postfix is triggering here, and why it gets to 120 before finally giving up? All my limits are standard so soft limit should be 10. It also ends on a "MAIL" command (same one it's already sent successfully 120 times), and I don't see any rejected addresses which rules out my theory that it eventually builds up to a certain number of rejected recipients.
Obviously this appears to be a client problem but it would be useful to know exactly why Postfix gives up at this point.
Thanks for any help,
Matt
I've got a strange issue with a customer which has raised a couple of questions. The first isn't strictly Postfix related, although it's the cause of the second question and explains what's going on.
The disconnect log from one of their sessions looks like the following (74 separate emails sent) -
disconnect from unknown ehlo=1 auth=1 mail=148 rcpt=148 data=74 rset=75 quit=1 commands=448
Now the interesting thing to note is that it sends twice as many mail/rcpt commands as data, and 75 resets. This is because the client sends MAIL/RCPT/RSET once for each email, then does another RSET for good luck, then does a full MAIL/RCPT/DATA sequence for each email.
First question is has anyone seen anything like this? Client is apparently Outlook - and the emails do have a 'X-Mailer: Microsoft Outlook 14.0' header - so I'm generally ruling out my first thought of a dodgy client. I'm wondering if there's some sort of AV that could do this?
Anyway the second question is that in some cases, the log looks like this -
disconnect from unknown ehlo=1 auth=1 mail=120 rcpt=120 rset=120 commands=362
In this case it tried to send 120 emails, but on the 121st MAIL command, got kicked off with a 'too many errors' message. No errors are reported in the smtp connection, and nothing appears in the log other than the final "too many errors".
Can someone tell me what error Postfix is triggering here, and why it gets to 120 before finally giving up? All my limits are standard so soft limit should be 10. It also ends on a "MAIL" command (same one it's already sent successfully 120 times), and I don't see any rejected addresses which rules out my theory that it eventually builds up to a certain number of rejected recipients.
Obviously this appears to be a client problem but it would be useful to know exactly why Postfix gives up at this point.
Thanks for any help,
Matt