Checking before it matters.
WHAT TO TEST
Sending to major providers Whether messages arrive in the inbox or spam Whether authentication passes
HOW TO TEST
Send to addresses you control at several providers.
Check the inbox and the spam folder.
USING TESTING SERVICES
Services provide an address to send to and report on authentication, content and reputation.
Useful and thorough.
WHAT TO CHECK IN HEADERS
Whether SPF passed Whether DKIM passed Whether DMARC aligned
HOW TO SEE HEADERS
Most mail clients allow viewing the original message.
WHAT TO TEST SPECIFICALLY
Your form notifications Your order confirmations Your newsletter Ordinary mail from your account
Each may use a different sending route.
HOW OFTEN
After any change, and periodically regardless.
WHAT PEOPLE DISCOVER
That one of their sending sources has been failing for months.
