SMTP

Summary

SMTP (Simple Mail Transfer Protocol) is the only mail sending protocol our mail servers support, which is fine because it is the only sending protocol that most email clients allow.

Troubleshooting

The most common issues for mail clients to be unable to send messages are authentication and port number. All of our mail servers require authentication to be enabled (more details below) using the same username and password combination as the incoming server. Port numbers vary from platform to platform, except port 587 which is universally supports on all of our email servers.

Authentication

Authentication for SMTP is given different names on different email clients. On all versions of Outlook it is under More Settings > Outgoing Server > "My outgoing server requires authentication". For iOS enabled devices (iPhone and iPad) there is a dropdown menu called "Authentication" with four validation options; the correct option for our servers is "Password". Android powers smartphones and tablets have a checkbox labeled "Require Login" in the outgoing settings, this will have to be enabled. Apple Mail (or Mac Mail as some call it) uses the same options for authentication as iOS devices (set to password for our servers) but also requires username and password to be entered upon changing this setting.

Apple Mail Troubleshooting

Apple Mail handles SMTP in a unique way to begin with. It will have a list of SMTP servers you can configure individually that are shared among all configured email accounts. Additionally no two SMTP servers configured can be exactly the same, you should always delete unused duplicates.

Port number options for Apple Mail SMTP are Use Default (25, 465, 287) and Override default port. Even though 587 is included in the default setting you will want to override and set port 587 to make outgoing mail work.