Postfix: improper command pipelining after EHLO from unknown

October 14, 2014 20.7k views
csmarkus
By:
csmarkus

I am attempting to access my email via Thunderbird and I get the following in /var/log/mail.log

Oct 14 13:27:22 baal postfix/submission/smtpd[15559]: warning: hostname cuda1.p2pa.com does not resolve to address 69.24.39.162
Oct 14 13:27:22 baal postfix/submission/smtpd[15559]: connect from unknown[69.24.39.162]
Oct 14 13:27:22 baal postfix/submission/smtpd[15559]: improper command pipelining after EHLO from unknown[69.24.39.162]: QUIT\r\n
Oct 14 13:27:22 baal postfix/submission/smtpd[15559]: disconnect from unknown[69.24.39.162]

What is causing this?

Additionally I am also getting the following from Dovecot when it starts in /var/log/mail.err

Oct 14 12:05:35 baal dovecot: auth: Error: read(anvil-auth-penalty) failed: EOF
Oct 14 12:05:35 baal dovecot: auth: Error: net_connect_unix(anvil-auth-penalty) failed: Permission denied

This is the tutorial I followed: https://www.digitalocean.com/community/tutorials/how-to-configure-a-mail-server-using-postfix-dovecot-mysql-and-spamassasin

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4 Answers
c4xp December 19, 2014

For those who come here: I solved it by commenting out port=0 so that default imap settings becomes available /etc/dovecot/conf.d/10-master.conf:
service imap-login {
inet_listener imap {
#port = 0
}
...
}
I guessed correctly that somehow the imap protocol is being blocked somehow (You should also check the firewall) :)

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  • johnclark0987 August 9, 2016

    Thank you so much! I would have never have guessed this, I was thinking it was a permission error as it stated.

dorivalac October 16, 2014

I face the same trouble .... no way to solve it, i´m try everything over 5 hours

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pishva September 20, 2016

excellent solution. thanks a lot

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dismasc December 26, 2018

At first, I thought I was experiencing problem with my configuration. Found this blog, and followed it.

But then I realized, that it is the way that Thunderbird checks for email settings during the first setup. It first checks and connect to IMAP on port 25 then port 143.

Well, in my case, I did not open port 25 and only use port 143 for IMAP, so it would be obvious that whenever Thunderbird checks port 25, it got rejected and made this error shows up in the log, but I do not have problems with authentication nor SSL, so I am just going to leave this like now, because I believe that my configuration is correct.

Here is mine:

service imap-login {
inet_listener imap {
port = 143
}

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