What is SPF?
SPF stands for “Sender Policy Framework” and is an important spam protection procedure for sender authentication when sending emails.
SPF records are TXT records in a domain’s DNS settings, which define which servers can send emails for the domain’s mailboxes. The receiving server checks whether the received email comes from one of the authorized mail servers. If the SPF record information matches the sender information in the email, the email is delivered, otherwise, it is treated as spam and rejected.
The same applies to incoming emails, which our servers also check for existing SPF records. For example, if a Gmail sender sends an email via servers that are not authorized to send Gmail, the email will be rejected by our servers as spam.
If you want to use the SPF procedure, please create a corresponding record in your domain’s DNS settings in the “TXT” format with the content
"v=spf1 include:spf.routing.net -all".
You will find a complete overview of the SPF record syntax under SPF Record Syntax.