April 2, 2018
2:32 p.m.
The concern is not UTF-8 or ASCII, it's the occurrence such as empty group may had the message marked spam or killed. The message is in ASCII with correct syntax, but some detectors may consider it bad regardless.
Are you aware of anywhere this has actually happened? Spam filters do all sorts of odd things but I don't recall this, and I see no point in putting in warnings unless they're about real problems. Regards, John Levine, john.levine@standcore.com Standcore LLC