For me this one is unlikely to make too much of a difference as I’m the only user of the domain.
So basically anyone who uses your custom domain can impersonate other users of the custom domain? This is far less significant than the claim made in the Mailbox forum, that users of a Mailbox can impersonate other users of Mailbox.
But I don’t understand how this emailspoofing test is testing for this. It seems more like a test for detecting how a provider detects spoofed mail, rather than a providers capability in preventing its users from spoofing the identity of other users.
I wonder how other providers we recommend compare.
I setup a separate thread to compare this (as comparisons in this thread were removed my moderator).