In plain English
The record is a list published in your DNS. When mail arrives claiming to be from your domain, the receiving server checks whether the sending server appears on that list.
It has a hard limit of ten DNS lookups, which is the most common way SPF quietly breaks. Every new sending service added edges closer to it.
What to know
A DNS TXT record
Listing authorised senders.
Checked on receipt
Against the sending server's address.
Ten lookup limit
Exceeding it invalidates the record.
Needs updating
Every new sending service must be added.
Why it matters
SPF alone is not sufficient, because it does not survive forwarding and does not verify the visible sender address. It is one of three records that together do the job.
Common mistakes
×Exceeding the ten lookup limit.
×Two SPF records on one domain, which is invalid.
×Forgetting to add a new email service.
×Relying on SPF alone.
FAQs
What happens if SPF fails?
Delivery is less likely, and DMARC may instruct the receiver to reject the message.
Can I have two SPF records?
No. One record, with all senders included.
WRITTEN BY TARIQ SALLAM
Marketing Consultant. Entrepreneur. Content Creator.
I'm a marketing consultant, entrepreneur and content creator. I help businesses grow through practical marketing, websites, SEO, content and AI.
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