All emails are bounced back and not sent with Plesk Email Security enabled

[senthil]

Symptoms

• If Plesk Email Security is enabled on the server, all incoming emails are bounced back and
  all outgoing emails are not sent with the following error:
  
  Code Select Expand
  Reporting-MTA: dns; host.example.com
X-Postfix-Queue-ID: 0C3B9189ADCB
X-Postfix-Sender: rfc822; root@host.example.com
Arrival-Date: Mon, 8 Nov 2021 05:46:15

Final-Recipient: rfc822; root@localhost.localdomain
Original-Recipient: rfc822;root@host.example.net
Action: failed
Status: 4.3.2
Remote-MTA: dns; 127.0.0.1
Diagnostic-Code: smtp; 421 4.3.2 Service shutting down, closing channel
• /var/log/maillog file contains the following errors:
  
  Code Select Expand
  amavis[27832]: (27832-01) (!)lookup_sql: sql exec: err=1146,42S02,
DBD::mysql::st execute failed: Table'emailsecurity.users' doesn't exist
at (eval 132) line 173., ,

amavis[27832] (27832-01) (!!)TROUBLE in process_request: sql exec: err=1146,
42S02, DBD::mysql::st execute failed: Table  'emailsecurity.users' doesn't exist
at (eval 132) line 173. at (eval 134) line 333.

amavis[27832]: (27832-01) (!)Requesting process rundown afterfatal error

postfix/smtp[27793]: 52B14194BE9D: to=jdoe@example.com,
relay=127.0.0.1[127.0.0.1]:10024, delay=139040, delays=139040/0.31/0.09/0.01,
 dsn=4.3.2, status=deferred(host 127.0.0.1[127.0.0.1] said: 421 4.3.2 Service
shuttingdown, closing channel (in reply to RCPT TO command))

Cause
Corrupted Email Security database

Resolution

• Log in to Plesk
• Remove and reinstall the Plesk Email Security extension: How to manage Plesk extensions (install, disable, remove, update)