If you get a ‘Connection Timed out’ error when sending email via our SMTP relay, it means that you are using an smtp port that is blocked. By default, we recommend using port 25 when sending emails via our SMTP relay.
However, some ISPs may block port 25. If this is the case, try using port 587. Ports 465 and 588 can also work, but make sure to test 465 first with SSL enabled to secure your sending. 588 won't support SSL. You can find this port information on your SMTP Settings page.
If you are using your own server with our SMTP relay, you can use this snippet of code to test which ports are open before you try sending.
If you are using your own server with our SMTP relay, you can use this snippet of code to test which ports are open before you try sending.