Anything that sends as you.
WHAT SENDS AS YOUR DOMAIN
Your mail server Marketing and newsletter platforms Your website, for form notifications and order emails Accounting and invoicing software Booking and helpdesk systems
WHAT EACH NEEDS
Inclusion in your SPF record Its own DKIM record, where the service provides one
WHAT HAPPENS WITHOUT IT
That service's mail fails authentication and lands in spam or is rejected.
THE COMMON SYMPTOM
Your personal mail arrives fine, but order confirmations or newsletters do not.
Different sending source, different authentication.
HOW TO SET IT UP
Each service documents what to add.
Follow it exactly.
THE SPF LIMIT
Each included service consumes a lookup.
Too many exceeds the limit and breaks SPF entirely.
WHAT TO DO ABOUT IT
Remove services you no longer use.
For many services, consider consolidating sending through one platform.
WHAT TO AUDIT
What actually sends as your domain. Most businesses have forgotten one.
