What is Port 25 blocking?

Port 25 blocking prevents spammers from sending masses of unauthorized junk email. Port 25 is the port or connection on your computer that outgoing email passes through.

Frontier blocks all SMTP (Port 25) traffic over our network that is not sent through Frontier outgoing mail servers (smtp.frontier.com). This only applies if you have a dynamic IP address.

If you’ve experienced a high level of spam, please change your outgoing mail server to smtp.frontier.com. You might also have to configure your email program to authenticate to our outgoing mail server. Learn more about setting up email through your computer or mobile device.

Note: Some customers telecommuting from home may be unable to send email using their companies’ email systems. We suggest establishing a secure connection via an application, such as VPN, in order to utilize the outgoing mail server for your place of business.