Webmail Error Connection timed out110 Can’t open SMTP stream.

Sometimes while sending the e-mails via webmail we are getting error as follows:

[wpfmb type=’error’ theme=2]ERROR: Message not sent. Server replied: Connection timed out110 Can’t open SMTP stream.[/wpfmb]

Also when we login the webmail interface,It works well but when we compose the email and click on send email, the interface stuck.

The possible reason that the server firewall ( csf ) might be blocking the SMTP

For this we’ll need to check the csf configuration file /etc/csf/csf.conf
and check for the parameter “SMTP_BLOCK”

If it is set to


It is enabled thereby it will block outgoing SMTP.

Please turn it to


And webmail will start working perfectly.