Web, domains and email
SPF
Abbreviation for Sender Policy Framework
In short and in plain language
SPF is an entry for a domain on the internet.
It sets out which servers may send email for this domain.
If it is missing or wrong, emails easily end up in spam. This can happen, for example, with emails from a contact form.
Definition
The Sender Policy Framework is a DNS record of a domain that specifies which servers may send email for that domain. If it is missing or wrong, emails from a contact form, for example, easily end up in spam.