The fundamentals.
WHAT RECEIVING SERVERS DECIDE
Whether to accept your mail Whether to deliver it to the inbox or the spam folder Whether to reject it entirely
WHAT THEY CONSIDER
Whether your domain is authorised to send Whether the message is signed Your sending reputation What recipients do with your mail The content itself
WHAT MATTERS MOST
Authentication and reputation.
Content matters far less than people assume.
THE COMMON MISCONCEPTION
That certain words trigger spam filters.
Modern filtering is largely about who is sending, not what is written.
WHAT THIS MEANS
Rewriting your message rarely fixes a delivery problem.
Fixing your authentication usually does.
WHAT AFFECTS YOUR REPUTATION
How many recipients mark you as spam How many addresses bounce How many people open and reply Whether you send to people who asked
WHERE TO START
Check your authentication records.
That is the foundation everything else rests on.
