SPF (Sender Policy Framework) is a public list - kept in your domain's DNS - of every mail server that's allowed to send email using your domain. Recipient servers check that list and reject or flag anything sent from a server that isn't on it.
Who does this: Marketing owns the outcome. IT (or your DNS provider) publishes the TXT record
Time needed: 2 minutes to read; publish takes an IT ticket plus up to 24 hours for DNS to propagate
Why this matters: SPF is how Gmail, Outlook, and Yahoo verify that Act-On is allowed to send mail in your name. Without it, most recipient servers assume Act-On is impersonating you and route your campaigns to spam - or refuse them outright.
In plain English: SPF is the guest list at the door. If the sender's name isn't on it, the message doesn't come in.
SPF is one of the primary defences against spoofing - somebody pretending to be you. Together with DKIM, it's how Act-On proves to recipient servers that it has permission to send email for your domain. SPF alone doesn't guarantee the inbox, but without it your chances of being sent to spam or rejected go up sharply.
Where SPF gets configured in Act-On
You need SPF published for both of these:
-
Envelope From Domain Setup - the routing domain (for example,
mailer.company.com). - Email From Setup - every domain you use in the visible From address.
Enabling both is what the mailbox providers check for when deciding whether to deliver.