My mail isn't sending — how to fix outgoing (SMTP) problems

If you can receive mail but messages won't send, the problem is almost always with the outgoing (SMTP) settings in your app rather than with the mailbox itself. Work through these checks:

1. Outgoing server authentication. The most common cause: your app must be told to authenticate (log in) on the outgoing server, using the same username and password as for incoming mail. If 'My outgoing server requires authentication' is switched off, turn it on.
2. The right SMTP server and port. Confirm the outgoing server name and port match exactly the settings we supplied. A wrong port or a missing SSL/TLS setting will block sending.
3. Your password. If you've recently changed it, update it in both the incoming and outgoing sections of the app.
4. A network that blocks sending. Some hotel, café and mobile networks block outgoing mail ports. Try another network — if it sends elsewhere, the network was the problem.

If sending still fails after these checks, send us the exact error message your app shows and we'll pin it down.