Applicable to:
- Plesk for Linux
Symptoms
- Unable to connect mail client on SMTPS port 465/993 SSL/TLS connection. Mail client displays the error:
Your server has unexpectedly terminated the connection. Possible causes for this include server problems, network problems, or a long period of inactivity. Account: 'my email', Server: '3.4.5.6', Protocol: SMTP, Port: 465, Secure(SSL): Yes, Error Number: 0x800CCC0F
-
Following error message is present in
/usr/local/psa/var/log/maillog:postfix/smtpd[31990]: warning: TLS library problem: 31990:error:14094418:SSL routines:SSL3_READ_BYTES:tlsv1 alert unknown ca:s3_pkt.c:1197:SSL alert number 48:
postfix/smtpd[31990]: lost connection after CONNECT from unknown[1.2.3.4]
postfix/smtpd[31990]: disconnect from unknown[1.2.3.4] -
Mail client displays the following error:
Your server has unexpectedly terminated the connection. Possible causes for this include server problems, network problems, or a long period of inactivity. Account: 'my email', Server: '3.4.5.6', Protocol: SMTP, Port: 465, Secure(SSL): Yes, Error Number: 0x800CCC0F
Cause
SSL CA certificates bundle is missing or corrupted.
Resolution
-
Install a valid certificate using the article Plesk following the instructions here: How to secure mail server with Let's Encrypt certificate
-
Connect to the server via SSH.
-
Run the following command:
# plesk repair mail
- In case this issue still persists, reinstall
ca-certificatespackage.For example, for CentOS 6:
# rpm -Uhv ca-certificates-2010.63-3.el6_1.5.noarch
Comments
4 comments
#plesk repair mail
Repairing the mail server configuration
Reconfigure all domains and mailboxes? [Y/n]
--------
What will be reconfigured and will the mailboxes and messages be retained?
Hello,
You can check what plesk repair mail utility from the the following link to our documentation:
https://docs.plesk.com/en-US/onyx/administrator-guide/plesk-administration/plesk-repair-utility/plesk-repair-utility-mail.74652/
The messages from the mailboxes will not be removed by running the utility.
Hi
I am facing the same problem but repair mail doesn't work.
I have installed let's encrypt on webmail, and since then I can't send email using PHPMailer (SMTP connect error)
maillog says :
SSL_accept error from localhost.localdomain[127.0.0.1]: -1
warning: TLS library problem: 27872:error:140760FC:SSL routines:SSL23_GET_CLIENT_HELLO:unknown protocol:s23_srvr.c:640:
lost connection after STARTTLS from localhost.localdomain[127.0.0.1]
it works fine on another server on which I didn't secure webmail. So I think the problem comes from let's encrypt
@frederic bigot,
I would suggest contacting our Technical Support Team for assistance, so they can check the issue in details.
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