Diagnosing a change.
FIRST, CONFIRM IT
Compare open rates over several sends. A single poor send is noise.
A sustained drop across sends is real.
CHECK IN THIS ORDER
- Authentication: did an SPF or DKIM record change, or did you add a sender without updating SPF
- Blacklists: is your domain or sending address listed
- Your platform's reports: has the complaint or bounce rate risen
- Recent changes: a new platform, a new sending address, a changed domain
THE COMMON CAUSES
An SPF record edited and broken A second SPF record added, which invalidates both A campaign to an old or purchased list, generating complaints A compromised account sending spam Sending volume increasing suddenly
IF IT IS AUTHENTICATION
Fix the records and test. Delivery usually recovers within days.
IF IT IS REPUTATION
Slower. Stop sending to inactive addresses, remove bounces, and send only to engaged subscribers for a period.
Recovery takes weeks of good behaviour.
IF YOUR ACCOUNT WAS COMPROMISED
Change credentials, check what was sent, and expect a longer recovery.
