One other detail in case it's relevant. The majority of subscribers
have a display name.
https://en.wikipedia.org/wiki/Email_address#Syntax

Note the remark about Display Name spoofing. With my name being
obvious from the address, I don't set the display-name in MUA
configuration.

Regards,                        ... P.

--
VoIP: +1 604 670 0140
work: https://en.wikibooks.org/wiki/User:PeterEasthope