Dovecot IMAP Failed - Waiting for authentication process to respond

[Jeff_Mash]

Hi guys - I found a couple other threads about this, but there were no solutions provided.

At least twice a day, our server is hanging (usually after we send an email to our 8,000 person mailing list). I suspect it may have something to do with processing all the bounced back emails we get from old email addresses.

I also notice that when it hangs, my MEMORY USAGE is almost completely consumed (only 111MB available).

Anyway, cPanel Service Monitor sends me messages that look like this. Could you PLEASE offer me some troubleshooting configurations to help eliminate this problem:

NOTIFICATION: IMAP Failed

Service Check Method: [socket connect]

Reason:

TCP Transaction Log:
<< * OK [CAPABILITY IMAP4rev1 LITERAL+ SASL-IR LOGIN-REFERRALS ID ENABLE STARTTLS AUTH=PLAIN AUTH=LOGIN] Dovecot ready.
>> A001 LOGIN __cpanel__service__auth__imap__VkxJfupuXRlZ6_D_ktQFfl3rPVpFjPSlKgTkc0TG_5m_DPk2aueyG3U6X2y0Yfm0 iz04hATwUr7ZATsfg20cENpXUBvNUybXNcNl6R7GCF6MrKi3InUH_o8BzNcwnU_N
<< * OK Waiting for authentication process to respond..
imap: ** [* OK Waiting for authentication process to respond.. != A001 OK]
: Died at /usr/local/cpanel/Cpanel/TailWatch/ChkServd.pm line 865, <$socket_scc> line 2.


Syslog Messages:

Mar 19 03:24:43 myjokemailcom dovecot: IMAP(__cpanel__service__auth__imap__vkxjfupuxrlz6_d_ktqffl3rpvpfjpslkgtkc0tg_5m_dpk2aueyg3u6x2y0yfm0): Connection closed bytes=0/294
Mar 19 03:24:30 myjokemailcom dovecot: imap-login: Login: user=<__cpanel__service__auth__imap__vkxjfupuxrlz6_d_ktqffl3rpvpfjpslkgtkc0tg_5m_dp...>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, secured
Mar 19 03:16:16 myjokemailcom dovecot: IMAP(__cpanel__service__auth__imap__ffn84h3jj5nh7gkclkitowngknl9wfarqllbcpdafjxxca_bzavvsklzdjflxrdl): Connection closed bytes=0/294
Mar 19 03:15:27 myjokemailcom dovecot: imap-login: Login: user=<__cpanel__service__auth__imap__ffn84h3jj5nh7gkclkitowngknl9wfarqllbcpdafjxxca...>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, secured
Mar 19 03:01:01 myjokemailcom dovecot: imap-login: Disconnected (auth failed, 1 attempts): user=<__cpanel__service__auth__imap__8nN5wZ5FFSNHRW1SsXv5wtAJL52MZG94GFfoRNF16UURNO...>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, secured

Memory Information:
Used: 1916MB
Available: 111MB
Installed: 2026MB

 

[Jeff_Mash]

Oh, and in case this helps, here are my settings under WHM --> Service Configuration --> Mailserver Configuration. If you think these should be adjusted to handle the problem above, please let me know what to try. I'm desperate over here!

Maximum Number of Mail Processes: 512

Maximum Size of a Mail Process (MB): 256

Maximum IMAP Connections Per IP: 20

Number of Spare Authentication Processes: 2

Maximum Number of Authentication Processes: 50

Maximum Size of a Authentication Process (MB): 64

Size of Authentication Cache (KB): 1024

Time to Cache Successful Logins: 3600

Time to Cache Failed Logins: 3600

Use New Authentication Process for Each Connection: NO

Idle Check Interval: 30