If you encounter such error while sending mails as :
“Horde error :Failed to set sender: [email protected] [SMTP: Failed to write to socket: not connected (code: -1, response: )]”
Check “SMTP_Block” option in CSF configuration file.
Make sure that “SMTP_Block” is set to “0”. So that it will not Block outgoing SMTP.
Restart CSF Firewall once the changes have been made.
Please fill in your email address to get most latest updates.