Honestly - don’t. Not unless you intend to be their 24/7 tech support…

It surprises me how often that point is lost… that said, of all people, you’d hope a priest would know better :(

Pretty sure there isn’t a single Catholic among them that would tell you such actions weren’t sinning…

True, but it presumably would still require the user to open them.

But, I was mostly worried that just having the server installed would be enough.

It’s only if you view a specifically crafted email in the web client… still worth upgrading of course.