Unable to send mail from Plesk server: deferred (delivery temporarily suspended: connect to 127.0.0.1[127.0.0.1]:10024: Connection refused)

Symptoms

• Unable to send emails. The following error is found on /var/log/maillog:

  status=deferred (delivery temporarily suspended: connect to 127.0.0.1[127.0.0.1]:10024: Connection refused)

• There are packages to be installed at Plesk > Extensions > Plesk Email Security. However, after installing them, amavisd is still not installed:

  # rpm -qa | grep amavisd
  #

Cause

The amavisd package is missing.

Resolution

1. Connect to the server via SSH.

2. Install amavisd:

   # yum install amavisd-new

3. Enable and start amavisd:

   # systemctl enable amavisd && systemctl start amavisd

4. Restart Postfix:

   # systemctl restart postfix

5. Requeue deferred emails:

   # postqueue -f