Email sent to me via webtrees (PHP Mail) has the from address in the format username@box###.myHost.com. My host describes this behavior at my.bluehost.com/cgi/help/206 and is seems (or at least implied by them) that the reason for this is that the email header is improperly set in webtrees, so the server defaults to a different address. From the support article:
Works
From: user@domain.com
From: "user" <user@domain.com>
Will Not Work
From: "user@domain.com"
From: user @ domain.com
From: user@domain.com <user@domain.com>
หมวกกันน็อค
I was unable to figure out what webtrees is actually trying to use, but I would hope it would be the name and email of the person (not a user in my tree) who is sending me the message in the format
Phyberd replied
345 weeks ago