STMP is not working.

Trying to use custom email as the sender, however STMP is not working so submitters do not receive confirmation emails. The settings seem to be correct as I have done this with other services, do I need to change any security settings or whitelist IP's?

Cheers

The only form on your account has our email address set as the Sender Email. Did you update the Sender Email? If the issue is related to some other form, please provide us a form URL.