I have a single mailbox mail server running Dovecot/Postfix and I have two IMAP clients, Thunderbird on the PC and K9 on Android. I keep on receiving this error in my logs even after I change the 'mail_max_userip_connections' variable to 50.

puppet dovecot: imap-login: Maximum number of connections from user+IP exceeded (mail_max_userip_connections=10): user=<admin@domain.net>, method=PLAIN, rip=, lip=, TLS

Why does it say that it is set to 10 in the log? Is that hardcoded?

grep -r "mail_max_userip_connections" /etc/dovecot
/etc/dovecot/conf.d/20-managesieve.conf:  #mail_max_userip_connections = 10
/etc/dovecot/conf.d/20-pop3.conf:  #mail_max_userip_connections = 3
/etc/dovecot/conf.d/20-imap.conf:  mail_max_userip_connections = 50

I've restarted dovecot after making the changes but this error is still logged and I can't access the mailbox. Can anyone help me understand why I can't seem to raise the maximum limit?

  • 1
    Is the shown line inside imap block?
    – Khaled
    May 2 '12 at 8:26

I recently had occasion to change this value, but I changed it in the main config file; in my /etc/dovecot/dovecot.conf it now says:

protocol imap {
  mail_max_userip_connections = 50

And it's been honoured; this is using dovecot 2.0.9 on a Centos 6.2 system. I don't know that that's an answer to your question, but I thought it might be useful for you to know that someone else had got it working, and how.

  • That seemed to work! Not sure why its not loading /etc/dovecot/conf.d/20-imap.conf, perhaps I need to explicitly define this in some load path. Thanks!
    – Michelle
    May 6 '12 at 13:24

Add mail_max_userip_connections = 50 in the global section, not in protocol imap or protocol pop3 sections. At least after doing so my dovecot -a started to return the requested value for mail_max_userip_connections and not the default 10.

I'm running Dovecot 2.0.9 on CentOS.


To me, the answer with the hint to the global section seemed to work.

Changed first only in ./conf.d subdirectory, but that didn't work and the E-Mail client continued in showing the error message as before with the value of 10 max connections. Tried a lot with always restarting the server, but as it was a brand new installation, I had to look into more details.

As this parameter wasn't set before, I inserted it here (dovecot.conf):


    # Protocols

    mail_max_userip_connections = 100

    !include_try /usr/share/dovecot/protocols.d/*.protocol

    protocol imap {
            mail_plugins = $mail_plugins imap_quota


May be, the value can be reduced later, but that needs testing as many devices are simultaneously checking for new mails.


If you use the separate configuration directory option of dovecot (for example, on my system, this setting is in /etc/dovecot/symbiosis.d/40-imap-settings/10-plugins),you need to do a make at the toplevel to merge all the separate files into one before you stop and start the server.

This answer applies to the bytemark symbiosis environment but others should be similar mutatis mutandis.

  • Based on the information in the question, the questioner is not using symbiosis.
    – womble
    Aug 7 '15 at 0:04
  • The symbiosis skin applies to debian and similar systems. The information should be usable in other systems (I don't think a particular system was identified) if they also use a Makefile to assemble the configs into a master config.
    – jrrk
    Aug 7 '15 at 19:57
  • Debian doesn't use a makefile to assemble a master config.
    – womble
    Aug 7 '15 at 22:50
  • From the package list, that would appear to be the case. But since the questioner does not mention a particular system, and the behaviour is so exactly like what I encountered on my bytemark on Debian system, I thought it would be reasonable to share my experience to see if it is relevant to the questioner.
    – jrrk
    Aug 8 '15 at 8:44

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