What Is SPF?
by Petras Surna
When you send an email you add a from address eg [email protected]
However, if your outgoing mail server is not *.abc.com.au (where * is mail or smtp etc), the email is not really coming from the abc.com.au domain.
A particular type of spam filter called SPF recognizes this and detects such email as malicious.
In general, your outgoing mail server will never be the same as your domain so if you are sending to a SPF detecting server you may get a message like this coming back to you:
550 failed to meet SPF requirements.
You can see this by looking at the message headers in the email, they may not be on the actual returned email itself.
How To Stop SPF Rejection
To fix this issue, you need to add a TXT record to your DNS via an IPv4 mechanism like this:
v=spf1 a mx ip4:18.104.22.168 –all
Where 22.214.171.124 is the IP of the outgoing mail server. You can get this address by looking at the message headers in the email, they may not be on the actual returned email itself.
This TXT record indicates that mail can be sent from any machine with an 'a' or 'mx' record in the domain you are modifying the DNS for, or from the IP address 126.96.36.199.
Allow 24 hours for the DNS record to propagate of course.