Lost Mail? "Turn of command pipelining" message

[ahotz]

I just fouund the following sequence in mail.log on my proxmox:

May 21 09:58:51 localhost postfix/smtp[24353]: 7538B40A40:  INTERNET@JANBOERSMA.NL>: Announcing remote <INTERNET@JANBOERSMA.NL> to sender failed: Unable to add recipient: 'INTERNET@JANBOERSMA.NL' 450 <INTERNET@JANBOERSMA.NL>: Recipient address rejected: Server maintenance. Try again later. (in reply to RCPT TO command)
May 21 09:58:51 localhost postfix/smtp[24353]: warning: 7538B40A40: non-ESMTP response from MX-HOST.DOT.tk[195.20.32.78]:25:
May 21 09:58:51 localhost postfix/smtp[24353]: warning: to prevent loss of mail, turn off command pipelining for 195.20.32.78
with the smtp_discard_ehlo_keyword_address_maps parameter

I don't know how to deal with this. In which way could "loss of mail" and what should I do? And does this mean I have to scan mail.log for such messages? Did I loose mail in the past because I missed such messages?

Regards Andreas

 

[dietmar]

450 <INTERNET@JANBOERSMA.NL>: Recipient address rejected: Server maintenance. Try again later. (in reply to RCPT TO command)

I don't know how to deal with this. In which way could "loss of mail" and what should I do? And does this mean I have to scan mail.log for such messages? Did I loose mail in the past because I missed such messages?

Regards Andreas

The remote server was obviously down (server maintainance), and responds with an unusual behaviour. But I dont think you loose any mail, because an error code '450' is a temporary error, i.e. the mail is sent again later (proxmox will try to deliver the mail more than once). You will get an report if the mail can't get delivered after 5 days.

You will also get delay warnings if you set MailProxy/DelayWaringTime (4 hours is usually a good value).

- Dietmar

 

[ahotz]

Not sure about this

Hello Dietmar

Thanks for the quick answer. However, I doubt that all is well. I've seen delay warnings by the thousands, and I'm not concerned about them. I suspect lots of other systems do the same thing as Proxmod does - Greylisting. So my question is not really about the 450 message. What puzzles me is the second and third line I posted, especially the action which ist suggested (setting some variable in the configuration).

Furthermore, I just checked my proxmox log again now (several hours later), and Proxmox did NOT try to resend the message. So the message has already been sent (which I doubt, according to the log) or has been lost (which is indicated by the warning about possible loss of mails

So what about the "non-ESMTP" logentry and the thing about turning off of pilelinnig? And what about the message - I find twho entries with the 450 message separated by 2 seconds, and then nothing more. The mail proxmox tried to send is obviously not there anymore.

Regards Andreas

 

[dietmar]

So what about the "non-ESMTP" logentry and the thing about turning off of pilelinnig? And what about the message - I find twho entries with the 450 message separated by 2 seconds, and then nothing more. The mail proxmox tried to send is obviously not there anymore.

The remote server was obviously down (server maintainance), and responds with an unusual behaviour.

Ask them why their server is down first.

- Dietmar

 

[dietmar]

It looks like they are aware of the problem - The changed their MX host to

mail.JANBOERSMA.NL. 3554 IN A 195.20.9.91

Do you still have problems with that domain?

- Dietmar