joined:Mar 15, 2013
I'm trying to go through every step possible to make sure my user-requested email is delivered.
It turns out that there are a bajillion potential mail headers:
So far, I'm setting To, From, Date, Message-ID, and Subject, but still being filtered as spam by Gmail (even though I have a +0.1 SpamAssassin score, a 100 SenderScore, and Mail-Tester.com gives me a 10/10... grrr).
What other headers might I want to consider adding to make sure I'm not getting filtered?