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

[felix1337]

Hello ,
since yesterday evening my mail server (Dovecot) seems not to work properly anymore. I tried to log in via webmail.example.com and I get the message: "Connection to storage server failed". Also all my mailboxes in Thunderbird show "Connection refused".

My system specifications:
OS: Ubuntu 18.04.4 LTS
Product: Plesk Obsidian 18.0.26

Thereupon I came across the following post describing my problem:

[FIXED BUG] Unable to log in to Roundcube webmail after upgrade to Plesk Onyx 17.8: Connection to storage server failed

I have renewed all certificates with "Lets Encrypt" in the menu item "Tools & Settings" -> "SSL/TLS Certificates" (Certificate for securing mail & Certificate for securing Plesk).
This step brought no improvement. My firewall is deactivated but my connection is denied by telnet (openssl s_client -connect myHost.com:993).

I have not made any changes in my Plesk system. This error occurred from yesterday to today.

So It probably seems to be an expired certificate?

I have no further idea what to do now.
Here again is the error I get from Roundcube:

[28-Apr-2020 13:34:53 UTC] PHP Warning: stream_socket_client(): unable to connect to ssl://localhost:993 (Connection refused) in /usr/share/psa-roundcube/program/lib/Roundcube/rcube_imap_generic.php on line 993
[28-Apr-2020 13:34:53 +0000]: <0uttuqkm> IMAP Error: Login failed for 567 against localhost from 77.64.145.187(X-Real-IP: 77.64.145.187). Could not connect to ssl://localhost:993: Connection refused in /usr/share/psa-roundcube/program/lib/Roundcube/rcube_imap.php on line 200 (POST /?_task=login&_action=login)


Best regards,
Felix

 

[IgorG]

Please check that Dovecot is not listening on the default ports 143 and 993, and it's binding on 9143 and 9993 ports instead:

# netstat -putan | grep dovecot
tcp 0 0 127.0.0.1:9143 0.0.0.0:* LISTEN 17638/dovecot
tcp 0 0 127.0.0.1:9993 0.0.0.0:* LISTEN 17638/dovecot

Also, Plesk Premium Email extension is installed, right?
And, please check the output of following command:

# systemctl status qmail

 

[Cebina]

Please check that Dovecot is not listening on the default ports 143 and 993, and it's binding on 9143 and 9993 ports instead:

# netstat -putan | grep dovecot
tcp 0 0 127.0.0.1:9143 0.0.0.0:* LISTEN 17638/dovecot
tcp 0 0 127.0.0.1:9993 0.0.0.0:* LISTEN 17638/dovecot

Also, Plesk Premium Email extension is installed, right?
And, please check the output of following command:

# systemctl status qmail

Hallo Igor,
i take this Listen


root@h2830886:~# netstat -putan | grep dovecot
tcp 0 0 0.0.0.0:995 0.0.0.0:* LISTEN 328/dovecot
tcp 0 0 127.0.0.1:9993 0.0.0.0:* LISTEN 328/dovecot
tcp 0 0 0.0.0.0:110 0.0.0.0:* LISTEN 328/dovecot
tcp 0 0 127.0.0.1:9143 0.0.0.0:* LISTEN 328/dovecot
tcp 0 0 0.0.0.0:4190 0.0.0.0:* LISTEN 328/dovecot
tcp6 0 0 :::995 :::* LISTEN 328/dovecot
tcp6 0 0 :::110 :::* LISTEN 328/dovecot
tcp6 0 0 :::4190 :::* LISTEN 328/dovecot

 

[IgorG]

What about my other questions?

 

[Cebina]

What about my other questions?

Plesk Premium Email extension is installed, right? not installed!!
root@h2830886:~# systemctl status qmail
Unit qmail.service could not be found.

 

[IgorG]

Could not connect to ssl://localhost:993: Connection refused

As you can see Rouncube tries to connect to 993 port, but your Dovecot works on 9993 port for some reason:

tcp 0 0 127.0.0.1:9993 0.0.0.0:* LISTEN 328/dovecot

Have you changed something in default settings?

 

[Cebina]

As you can see Rouncube tries to connect to 993 port, but your Dovecot works on 9993 port for some reason:

Have you changed something in default settings?

i have not changed !

 

[Cebina]

As you can see Rouncube tries to connect to 993 port, but your Dovecot works on 9993 port for some reason:

Have you changed something in default settings?

where should I check that?

 

[IgorG]

What is the output of command

# plesk bin extension --list | grep -i kolab

?

 

[Cebina]

What is the output of command

# plesk bin extension --list | grep -i kolab

?

root@h2830886:~# plesk bin extension --list | grep -i kolab
kolab - Plesk Premium Email, powered by Kolab

 

[IgorG]

In this case why you wrote:

not installed!!

Uninstall this extension and check that Dovecot works on 993 port instead of 9993 with

# netstat -putan | grep dovecot

 

[Cebina]

here i plesk roundcube errors log,
Could not connect to ssl://localhost:993: Verbindungsaufbau abgelehnt in /usr/share/psa-roundcube/program/lib/Roundcube/rcube_imap.php on line 200 (POST /roundcube/?_task=login&_action=login)

 

[IgorG]

here i plesk roundcube errors log,
Could not connect to ssl://localhost:993: Verbindungsaufbau abgelehnt in /usr/share/psa-roundcube/program/lib/Roundcube/rcube_imap.php on line 200 (POST /roundcube/?_task=login&_action=login)

I know. Please follow my last instruction.

 

[Cebina]

I know. Please follow my last instruction.

In this case why you wrote:


Uninstall this extension and check that Dovecot works on 993 port instead of 9993 with

# netstat -putan | grep dovecot

root@h2830886:~# plesk bin extension --list | grep -i kolab
root@h2830886:~# netstat -putan | grep dovecot
tcp 0 0 0.0.0.0:993 0.0.0.0:* LISTEN 7694/dovecot
tcp 0 0 0.0.0.0:995 0.0.0.0:* LISTEN 7694/dovecot
tcp 0 0 0.0.0.0:110 0.0.0.0:* LISTEN 7694/dovecot
tcp 0 0 0.0.0.0:143 0.0.0.0:* LISTEN 7694/dovecot
tcp 0 0 0.0.0.0:4190 0.0.0.0:* LISTEN 7694/dovecot
tcp6 0 0 :::993 :::* LISTEN 7694/dovecot
tcp6 0 0 :::995 :::* LISTEN 7694/dovecot
tcp6 0 0 :::110 :::* LISTEN 7694/dovecot
tcp6 0 0 :::143 :::* LISTEN 7694/dovecot
tcp6 0 0 :::4190 :::* LISTEN 7694/dovecot
root@h2830886:~#

 

[Cebina]

its work now Thank you somuch!!!

 

[robertne]

Hi i have same error but my server is listening on port 993
LOGS:

[23-Nov-2022 07:29:46 UTC] PHP Warning: stream_socket_client(): SSL: Connection reset by peer in /usr/share/psa-roundcube/program/lib/Roundcube/rcube_imap_generic.php on line 1060
[23-Nov-2022 07:29:46 UTC] PHP Warning: stream_socket_client(): Failed to enable crypto in /usr/share/psa-roundcube/program/lib/Roundcube/rcube_imap_generic.php on line 1060
[23-Nov-2022 07:29:46 UTC] PHP Warning: stream_socket_client(): unable to connect to ssl://localhost:993 (Unknown error) in /usr/share/psa-roundcube/program/lib/Roundcube/rcube_imap_generic.php on line 1060
[23-Nov-2022 07:29:46 +0000]: <a9s7uaq0> IMAP Error: Login failed for [email protected] against localhost from xxx.xxx.xxx.xxx (X-Forwarded-For: 190.210.65.230). Could not connect to ssl://localhost:993: Unknown reason in /usr/share/psa-roundcube/program/lib/Roundcube/rcube_imap.php on line 211 (POST /?_task=login&_action=login)

and netstat -putan | grep dovecot shows

tcp 0 0 0.0.0.0:993 0.0.0.0:* LISTEN 593/dovecot
tcp 0 0 0.0.0.0:995 0.0.0.0:* LISTEN 593/dovecot
tcp 0 0 0.0.0.0:110 0.0.0.0:* LISTEN 593/dovecot
tcp 0 0 0.0.0.0:143 0.0.0.0:* LISTEN 593/dovecot
tcp 0 0 0.0.0.0:4190 0.0.0.0:* LISTEN 593/dovecot

this problem started after the last update of plesk