Issue Email Server failure every day

[swebsystems]

Server operating system version

Ubuntu 20.04

Plesk version and microupdate number

Obsidian 18.0.44

Good morning,
i have some trouble with my virtual server at Strato. Pleks Email is going down every day.
Ubuntu 20.04, 32GB Ram, 1000GB SSD.
When you go to webmail via Roundcube, the server has a 403 after the login.
To fix the problem it is enough to go to Email Server Options in Plesk and press ok.
I had never such trouble with my older server.
May be someone can help?

 

[sebgonzes]

Good morning,
i have some trouble with my virtual server at Strato. Pleks Email is going down every day.
Ubuntu 20.04, 32GB Ram, 1000GB SSD.
When you go to webmail via Roundcube, the server has a 403 after the login.
To fix the problem it is enough to go to Email Server Options in Plesk and press ok.
I had never such trouble with my older server.
May be someone can help?

Review the error_log, you should have more detail about the real problem. 403 error is an deny access...

 

[swebsystems]

where i can find the error_log?

 

[sebgonzes]

where i can find the error_log?

Horde log var log psa-horde psa-horde.log
Roundcube log var log plesk-roundcube errors
Plesk log usr local psa admin logs httpsd_access_log / panel.log
General apache error log var log httpd error_log
Check these files first.

 

[swebsystems]

Plesk Roundcube log

[13-Jun-2022 09:13:24 UTC] PHP Warning: stream_socket_client(): unable to connect to ssl://localhost:993 (Verbindungsaufbau abgelehnt) in /usr/share/psa-roundcube/program/lib/Roundcube/rcube_imap_generic.php on line 1025
[13-Jun-2022 09:13:24 +0000]: <q8o91g6l> IMAP Error: Login failed for [email protected] against localhost from 80.187.xxx.xxx. Could not connect to ssl://localhost:993: Verbindungsaufbau abgelehnt in /usr/share/psa-roundcube/program/lib/Roundcube/rcube_imap.php on line 200 (POST /?_task=login&_action=login)

 

[sebgonzes]

Plesk Roundcube log

[13-Jun-2022 09:13:24 UTC] PHP Warning: stream_socket_client(): unable to connect to ssl://localhost:993 (Verbindungsaufbau abgelehnt) in /usr/share/psa-roundcube/program/lib/Roundcube/rcube_imap_generic.php on line 1025
[13-Jun-2022 09:13:24 +0000]: <q8o91g6l> IMAP Error: Login failed for [email protected] against localhost from 80.187.xxx.xxx. Could not connect to ssl://localhost:993: Verbindungsaufbau abgelehnt in /usr/share/psa-roundcube/program/lib/Roundcube/rcube_imap.php on line 200 (POST /?_task=login&_action=login)

Review this post : Resolved - Dovecot - unable to connect to ssl://localhost:993 - With fresh updates?

 

[swebsystems]

No Plesk Premium is installed

tcp6 0 0 :::110 :::* LISTEN 359/dovecot
tcp6 0 0 :::143 :::* LISTEN 359/dovecot
tcp6 0 0 :::4190 :::* LISTEN 359/dovecot
tcp6 0 0 :::993 :::* LISTEN 359/dovecot
tcp6 0 0 :::995 :::* LISTEN

 

[swebsystems]

Its also interesting, that with Thunderbird you dont have any connection, until you go to Plesk, Email Server, Options. But the mails are in the inbox after restart or ok in the email server settings. So the imap seems to be still working, but no connection.

 

[sebgonzes]

No Plesk Premium is installed

tcp6 0 0 :::110 :::* LISTEN 359/dovecot
tcp6 0 0 :::143 :::* LISTEN 359/dovecot
tcp6 0 0 :::4190 :::* LISTEN 359/dovecot
tcp6 0 0 :::993 :::* LISTEN 359/dovecot
tcp6 0 0 :::995 :::* LISTEN

No firewall enable? the unable to connect to ssl://localhost:993 message not seem normal .. what about telnet localhost 993 on your server?

 

[swebsystems]

Plesk Firewall is active. How can i check the localhost:993 port?

 

[sebgonzes]

Plesk Firewall is active. How can i check the localhost:993 port?

firstly, disable your firewall and check if you still have same problem
you can check the localhost 993 connection with

telnet localhost 993
you should have this return

# telnet localhost 993
Trying ::1...
Connected to localhost.
Escape character is '^]'.

 

[swebsystems]

root@h2971026:~# telnet localhost 993
Trying ::1...
Connected to localhost.localdomain.
Escape character is '^]'.

 

[sebgonzes]

root@h2971026:~# telnet localhost 993
Trying ::1...
Connected to localhost.localdomain.
Escape character is '^]'.

your imap ssl connection seem ok, at this point, suppose the better way if you have no sysadmin that can check directly the issue on your server when you get the failure, is to contact plesk with an ticket to review your case.

 

[swebsystems]

I'll try tomorrow without the Firewall, and give a short information about it. Thx a lot

 

[mow]

root@h2971026:~# telnet localhost 993
Trying ::1...
Connected to localhost.localdomain.
Escape character is '^]'.

Did you try this when you have the problem?

Also, run ss -putain|grep 993 while you have the problem.

 

[swebsystems]

Did you try this when you have the problem?

Also, run ss -putain|grep 993 while you have the problem.

No but i'll try it tomorrow when there are any problems today. Thx

 

[swebsystems]

This morning

2022-06-22 08:34:41 dovecot master: Error: service(imap-login): command startup failed, throttling for 16.000 secs 2022-06-22 08:34:40 dovecot master: Error: service(imap-login): fork() failed: Resource temporarily unavailable (ulimit -u 62987 reached?) 2022-06-22 08:34:39 dovecot master: Error: service(imap): command startup failed, throttling for 16.000 secs 2022-06-22 08:34:39 dovecot master: Error: service(imap): fork() failed: Resource temporarily unavailable (ulimit -u 62987 reached?) 2022-06-22 08:34:32 dovecot master: Error: service(imap-login): command startup failed, throttling for 8.000 secs 2022-06-22 08:34:32 dovecot master: Error: service(imap-login): fork() failed: Resource temporarily unavailable (ulimit -u 62987 reached?) 2022-06-22 08:34:31 dovecot master: Error: service(imap): command startup failed, throttling for 8.000 secs 2022-06-22 08:34:31 dovecot master: Error: service(imap): fork() failed: Resource temporarily unavailable (ulimit -u 62987 reached?) 2022-06-22 08:34:28 dovecot master: Error: service(imap-login): command startup failed, throttling for 4.000 secs 2022-06-22 08:34:28 dovecot master: Error: service(imap-login): fork() failed: Resource temporarily unavailable (ulimit -u 62987 reached?) 2022-06-22 08:34:27 dovecot master: Error: service(imap): command startup failed, throttling for 4.000 secs 2022-06-22 08:34:27 dovecot master: Error: service(imap): fork() failed: Resource temporarily unavailable (ulimit -u 62987 reached?) 2022-06-22 08:34:26 dovecot master: Error: service(imap-login): command startup failed, throttling for 2.000 secs 2022-06-22 08:34:26 dovecot master: Error: service(imap-login): fork() failed: Resource temporarily unavailable (ulimit -u 62987 reached?) 2022-06-22 08:34:25 dovecot master: Error: service(imap): command startup failed, throttling for 2.000 secs 2022-06-22 08:34:25 dovecot master: Error: service(imap): fork() failed: Resource temporarily unavailable (ulimit -u 62987 reached?)

 

[swebsystems]

Issue - Dovecot IMAP Mail error - No SSL-Connection over Port 993

Hello, I an error with my dovecot mailserver on Plesk. Even if I want to load the Emails over the Apple Mail or Outlook Client, I'm getting the following error: "Mail could not establish an SSL connection to the server "example.tld" via the standard ports. Make sure that this server supports...

talk.plesk.com

I believe that this is still the problem. Ill check this and give a response.

 

[JogoVogo]

1. View the contents of /etc/systemd/system.conf to know the current DefaultTasksMax value. Alternatively, run the following command:
   systemctl show --property DefaultTasksMax
   
   
2. If your DefaultTasksMax value is not 65535, then uncomment the line in /etc/systemd/system.conf and set the value to 65535.
   
   
3. To enable the new settings, reboot your system or run the following command:
   systemctl daemon-reload

 

[httPete]

Hello all,

I am joining this thread because I have a similar problem with my mail server. Periodically I get a message via watchdog that my IMAP and POP3 service is down and restarted after a few seconds (about 30-45). This can happen up to 2 times a day. Some days the problem does not occur.

Here is the email I receive via watchdog:
The Dovecot IMAP and POP3 server service on host "hostname" is down.
The problem was discovered on Sep 14, 2022 08:48 PM.

After looking at the logs "/var/log/mail.err", I personally (with my knowledge) cannot find an exact error. At least I can't find much information about the messages.

The logfile says the following:

Sep 14 20:44:57 h2873876 dovecot: master: Error: service(imap): fork() failed: Resource temporarily unavailable (ulimit -u 62987 reached?)
Sep 14 20:44:57 h2873876 dovecot: master: Error: service(imap): command startup failed, throttling for 2.000 secs
Sep 14 20:44:59 h2873876 dovecot: master: Error: service(imap): fork() failed: Resource temporarily unavailable (ulimit -u 62987 reached?)
Sep 14 20:44:59 h2873876 dovecot: master: Error: service(imap): command startup failed, throttling for 4.000 secs
Sep 14 20:45:03 h2873876 dovecot: master: Error: service(imap): fork() failed: Resource temporarily unavailable (ulimit -u 62987 reached?)
Sep 14 20:45:03 h2873876 dovecot: master: Error: service(imap): command startup failed, throttling for 8.000 secs
Sep 14 20:45:11 h2873876 dovecot: master: Error: service(imap): fork() failed: Resource temporarily unavailable (ulimit -u 62987 reached?)
Sep 14 20:45:11 h2873876 dovecot: master: Error: service(imap): command startup failed, throttling for 16.000 secs
Sep 14 20:45:27 h2873876 dovecot: master: Error: service(imap): fork() failed: Resource temporarily unavailable (ulimit -u 62987 reached?)
Sep 14 20:45:27 h2873876 dovecot: master: Error: service(imap): command startup failed, throttling for 32.000 secs
Sep 14 20:45:27 h2873876 dovecot: master: Error: service(imap-login): fork() failed: Resource temporarily unavailable (ulimit -u 62987 reached?)
Sep 14 20:45:27 h2873876 dovecot: master: Error: service(imap-login): command startup failed, throttling for 2.000 secs
Sep 14 20:45:29 h2873876 dovecot: master: Error: service(imap-login): fork() failed: Resource temporarily unavailable (ulimit -u 62987 reached?)
Sep 14 20:45:29 h2873876 dovecot: master: Error: service(imap-login): command startup failed, throttling for 4.000 secs
Sep 14 20:45:33 h2873876 dovecot: master: Error: service(imap-login): fork() failed: Resource temporarily unavailable (ulimit -u 62987 reached?)
Sep 14 20:45:33 h2873876 dovecot: master: Error: service(imap-login): command startup failed, throttling for 8.000 secs
Sep 14 20:45:41 h2873876 dovecot: master: Error: service(imap-login): fork() failed: Resource temporarily unavailable (ulimit -u 62987 reached?)
Sep 14 20:45:41 h2873876 dovecot: master: Error: service(imap-login): command startup failed, throttling for 16.000 secs
Sep 14 20:45:57 h2873876 dovecot: master: Error: service(imap-login): fork() failed: Resource temporarily unavailable (ulimit -u 62987 reached?)
Sep 14 20:45:57 h2873876 dovecot: master: Error: service(imap-login): command startup failed, throttling for 32.000 secs
Sep 14 20:45:59 h2873876 dovecot: master: Error: service(imap): fork() failed: Resource temporarily unavailable (ulimit -u 62987 reached?)
Sep 14 20:45:59 h2873876 dovecot: master: Error: service(imap): command startup failed, throttling for 60.000 secs
Sep 14 20:46:27 h2873876 dovecot: imap-login: Error: master(imap): Auth request timed out (client-pid=3420, client-id=1, rip=2003:d1:371b:1f00:7979:4f30:64d:b99, created 90059 msecs ago, received 0/4 bytes)
Sep 14 20:46:29 h2873876 dovecot: master: Error: service(imap-login): fork() failed: Resource temporarily unavailable (ulimit -u 62987 reached?)
Sep 14 20:46:29 h2873876 dovecot: master: Error: service(imap-login): command startup failed, throttling for 2.000 secs
Sep 14 20:46:31 h2873876 dovecot: master: Error: service(imap-login): fork() failed: Resource temporarily unavailable (ulimit -u 62987 reached?)
Sep 14 20:46:31 h2873876 dovecot: master: Error: service(imap-login): command startup failed, throttling for 2.000 secs
Sep 14 20:46:33 h2873876 dovecot: master: Error: service(imap-login): fork() failed: Resource temporarily unavailable (ulimit -u 62987 reached?)
Sep 14 20:46:33 h2873876 dovecot: master: Error: service(imap-login): command startup failed, throttling for 2.000 secs
Sep 14 20:46:35 h2873876 dovecot: master: Error: service(imap-login): fork() failed: Resource temporarily unavailable (ulimit -u 62987 reached?)
Sep 14 20:46:35 h2873876 dovecot: master: Error: service(imap-login): command startup failed, throttling for 2.000 secs
Sep 14 20:46:37 h2873876 dovecot: master: Error: service(imap-login): fork() failed: Resource temporarily unavailable (ulimit -u 62987 reached?)
Sep 14 20:46:37 h2873876 dovecot: master: Error: service(imap-login): command startup failed, throttling for 2.000 secs
Sep 14 20:46:39 h2873876 dovecot: master: Error: service(imap-login): fork() failed: Resource temporarily unavailable (ulimit -u 62987 reached?)
Sep 14 20:46:39 h2873876 dovecot: master: Error: service(imap-login): command startup failed, throttling for 4.000 secs
Sep 14 20:46:43 h2873876 dovecot: master: Error: service(imap-login): fork() failed: Resource temporarily unavailable (ulimit -u 62987 reached?)
Sep 14 20:46:43 h2873876 dovecot: master: Error: service(imap-login): command startup failed, throttling for 8.000 secs
Sep 14 20:46:51 h2873876 dovecot: master: Error: service(imap-login): fork() failed: Resource temporarily unavailable (ulimit -u 62987 reached?)
Sep 14 20:46:51 h2873876 dovecot: master: Error: service(imap-login): command startup failed, throttling for 16.000 secs
Sep 14 20:46:59 h2873876 dovecot: master: Error: service(imap): fork() failed: Resource temporarily unavailable (ulimit -u 62987 reached?)
Sep 14 20:46:59 h2873876 dovecot: master: Error: service(imap): command startup failed, throttling for 60.000 secs
Sep 14 20:47:07 h2873876 dovecot: master: Error: service(imap-login): fork() failed: Resource temporarily unavailable (ulimit -u 62987 reached?)
Sep 14 20:47:07 h2873876 dovecot: master: Error: service(imap-login): command startup failed, throttling for 32.000 secs
Sep 14 20:47:36 h2873876 psa-pc-remote[23523]: Message aborted.
Sep 14 20:47:36 h2873876 psa-pc-remote[23523]: Message aborted.
Sep 14 20:47:59 h2873876 dovecot: imap(3505): Error: Login client disconnected too early (connection created 0 msecs ago, client created 0 msecs ago: session=f3p9hqfoQOcgAwDRNxsfAHl5TzAGTQuZ, rip=2003:d1:371b:1f00:7979:4f30:64d:b99, auth_pid=3326, client-pid=3420, client-id=1)
Sep 14 20:47:59 h2873876 dovecot: imap(3505): Error: auth-master: login: request [2609250305]: Login auth request failed: Internal auth failure (auth connected 0 msecs ago, request took 0 msecs, client-pid=3420 client-id=1)
Sep 14 20:47:59 h2873876 dovecot: auth: Error: auth-master client: Master requested auth for nonexistent client 3420 (created 0 msecs ago, handshake 0 msecs ago)
Sep 14 20:47:59 h2873876 dovecot: master: Error: service(imap): fork() failed: Resource temporarily unavailable (ulimit -u 62987 reached?)
Sep 14 20:47:59 h2873876 dovecot: master: Error: service(imap): command startup failed, throttling for 2.000 secs
Sep 14 20:48:01 h2873876 dovecot: master: Error: service(imap): fork() failed: Resource temporarily unavailable (ulimit -u 62987 reached?)
Sep 14 20:48:01 h2873876 dovecot: master: Error: service(imap): command startup failed, throttling for 2.000 secs
Sep 14 20:48:03 h2873876 dovecot: master: Error: service(imap): fork() failed: Resource temporarily unavailable (ulimit -u 62987 reached?)
Sep 14 20:48:03 h2873876 dovecot: master: Error: service(imap): command startup failed, throttling for 4.000 secs
Sep 14 20:48:07 h2873876 dovecot: master: Error: service(imap): fork() failed: Resource temporarily unavailable (ulimit -u 62987 reached?)
Sep 14 20:48:07 h2873876 dovecot: master: Error: service(imap): command startup failed, throttling for 8.000 secs
Sep 14 20:48:15 h2873876 dovecot: master: Error: service(imap): fork() failed: Resource temporarily unavailable (ulimit -u 62987 reached?)
Sep 14 20:48:15 h2873876 dovecot: master: Error: service(imap): command startup failed, throttling for 16.000 secs
Sep 14 20:48:15 h2873876 dovecot: master: Error: service(pop3-login): fork() failed: Resource temporarily unavailable (ulimit -u 62987 reached?)
Sep 14 20:48:15 h2873876 dovecot: master: Error: service(pop3-login): command startup failed, throttling for 2.000 secs
Sep 14 20:48:16 h2873876 dovecot: imap-login: Error: master(imap): read() failed: Remote closed connection (destination service { process_limit } reached?) (client-pid=3504, client-id=1, rip=91.49.220.203, created 29538 msecs ago, received 0/4 bytes)
Sep 14 20:48:16 h2873876 dovecot: imap-login: Error: master(imap): read() failed: Remote closed connection (destination service { process_limit } reached?) (client-pid=3503, client-id=1, rip=91.49.220.203, created 29547 msecs ago, received 0/4 bytes)
Sep 14 20:48:16 h2873876 dovecot: imap-login: Error: master(imap): read() failed: Remote closed connection (destination service { process_limit } reached?) (client-pid=3502, client-id=1, rip=91.49.220.203, created 29560 msecs ago, received 0/4 bytes)

The output of "/etc/systemd/system.conf" shows that the line "DefaultTasksMax" is commented out:

#DefaultTasksMax=

systemctl show --property=DefaultTasksMax results
DefaultTasksMax=105

I used a Linux vServer:
Ubuntu 18.04.6 LTS
Plesk version 18.0.46 update #1

Provider also Strato.

Can anyone help me?