Issue Recurring Amavis timeout issue — "conversation with 127.0.0.1 timed out" recurring every N months

[mcbus94]

Server operating system version

AlmaLinux 9.8

Plesk version and microupdate number

Plesk Obsidian v18.0.79_build1800260720.04 os_RedHat el9

• Plesk Obsidian on AlmaLinux 9.8
• Amavisd 2.13.1-1.el9 (from EPEL)
• AMD EPYC 7313 (32 cores), 66GB RAM, nginx + PHP 8.4 FPM, MariaDB

Emails fail to send with the following error recurring every N months (pattern not yet identified):

4.4.2 deferred (delivery temporarily suspended: conversation with 127.0.0.1[127.0.0.1] timed out while receiving the initial server greeting)

Last occurrence (today, 24 Jul 2026):

• 130+ messages queued and blocked, spanning ~12 hours (from ~12:36 until now)
• All postfix SMTP processes show status "delivery temporarily suspended"
• Amavisd logs show: (!!)TROUBLE in child_init_hook: BDB can't connect db env. for multiple child processes

Temporary fix (applied successfully):
Following https://support.plesk.com/hc/en-us/articles/15657655076375, restarting services resolves it:

systemctl restart amavisd
systemctl restart postfix
postsuper -r ALL

Messages then process normally.

Problem recurs periodically (frequency TBD, likely monthly or quarterly). Is this a known issue with Amavisd 2.13.1 on AlmaLinux 9.8?

Thank you in advance

 

[Sebahat.hadzhi]

Hi, @mcbus94 . Does the issue appear in relatively the same time - is there any pattern you can catch, or does it appear randomly? Please check if OOM has occurred:

journalctl -k | grep -i -e memory -e oom

Also, you may use the sar utility to check CPU and system load:

sar -q 2 5

If unavailable, you can install it as follow:

yum install sysstat
service sysstat start

 

[mcbus94]

I can't define a specific time because I only notice the problem when I log into Plesk or in the evening I realize I haven't received a single email.
No memory and no cpu issue, we are using Plesk monitoring.

 

[Sebahat.hadzhi]

Thank you for the confirmation. Please navigate to Tools & Settings > Plesk Email Security > Server Settings > Advanced, and confirm if "Concurrent Amavis Processes" is set to the default value of 10. If yes, please try increasing it to 20, for example.