The only way I've been able to make the outgoing mail work is by connecting through port 465 using ssl. This works, but it seems odd to me. I've got port 25 open in the firewall, I'm just wondering if I've got something configured wrong. I've tried 587 too, but that didn't work either. Any suggestions? Port 25 blocking allows ISPs to block spam sent out through their networks, but it tends to punish the innocent that have a need to send through e-mail servers other than those belonging to their ISP. The ISPs that block port 25 require their SMTP server to be used instead of the remote SMTP server or a SMTP server running on your computer. The ISPs that block port 25 require their SMTP server to be used instead of the remote SMTP server; so you will need to change the outgoing mail server (SMTP) from the default Port 25 to Port 26. If you use Outlook (or any other email software/device), please be sure to select the option for Outgoing SMTP Server Requires Authentication . If it does not work (or your email program does not support changing the SMTP port) contact your system administrator / ISP about allowing outbound connections to our servers on ports: 23, 25, 26 or 2525. In the event our service does not solve your problem and you cannot send email we do offer a money back guarantee. Port 25 is the port or connection on your computer through which outgoing email must pass. Port 25 blocking prevents spammers from sending masses of unauthorized junk email. Frontier blocks all SMTP (Port 25) traffic over our network that is not sent through Frontier outgoing mail servers (smtp.frontier.com). You must bind the SMTP service to a port that is not occupied by any other service ; Goto Transaction SMICM -> Goto -> Services ; Select SMTP, goto 'Service' in the top left corner and then choose 'Change' Change the 'Service Port' to a free port and then hit the 'Change Service' green check mark (F8) and the SMTP service should be active Dec 14, 2017 · We just installed a brand new Cpanel server, and the Non-SSL connection on smtp port 25,26,587 is not working. SSL work fine on all the port. Maybe it's a new setting somewhere? I can't find anything work with the exim config

Dec 14, 2017 · We just installed a brand new Cpanel server, and the Non-SSL connection on smtp port 25,26,587 is not working. SSL work fine on all the port. Maybe it's a new setting somewhere? I can't find anything work with the exim config

Posts: 15 Joined: 6.Apr.2009 Status: offline uemurad, I appreciate your attempt to help me. The server is forwarding all outgoing, public email to an external smart host (the business' ISP mail server), so I assume SMTP outbound is working fine.

I've got pop and IMAP working for remote mail clients, but i can't seem to get the SMTP port working for sending mail. I have no problems connecting thru RWW to client computer and Outlook Web Access, or any of the other functions I've tried telnet to connect to port 25 but i just get "Connect failed".

To send SMTP email using Telnet: Start your session by typing in the terminal: TELNET smtp.sendgrid.net 25. SendGrid accepts unencrypted and TLS connections on ports 25, 587, & 2525. You can also connect via SSL on port 465. Many hosting providers and ISPs block port 25 as a default practice. Thanks, yes that's the obvious issue. It's been a valid account for 15+ years. My other ntlworld and virginmedia addresses work ok. Despite changing the password a number of times this has not fixed the issue including testing across multiple devices (before anyone points me to the usual help to fix an apple mail setting) which implies that either the directory services that the SMTP servers