Hi Dale and welcome to the UTM Community!

You didn't say which versions of iOS and UTM you're on.  If iOS 11, be sure to Up2Date to 9.506 - it's the first version of 9.5 that I recommend in general.

You'll want to consider doing #1 in Rulz.

Cheers - Bob

For what it's worth, Dale, we are also struggling with this issue. On our guest wireless network, where there's next to no filtering, we still can't use iOS mail to send or receive gmail. The Gmail app works fine, it's just the iOS mail that won't work.

A follow-up: we were limiting traffic on the guest wireless network to ports 80 and 443.

When we changed the rule to Any, iOS mail started working properly.

A follow-up: we were limiting traffic on the guest wireless network to ports 80 and 443.

When we changed the rule to Any, iOS mail started working properly.

Those visiting this thread might be interested in a document I maintain that I make available to members of the UTM Community, "Configure HTTP Proxy for a Network of Guests."  If you would like me to send you this document, PM me your email address.  I also maintain a version auf Deutsch initially translated by fellow member hallowach when he and I did a major revision in 2013.

Cheers - Bob