Result
Three building blocks against forged senders
SPF (Sender Policy Framework) lists the servers allowed to send for your domain. Important: an SPF record may trigger at most ten further DNS lookups, otherwise receivers treat it as broken. We resolve all includes and count along.
DKIM (DomainKeys Identified Mail) adds a digital signature to outgoing mail. The public key is found under a “selector”. If you don’t know it, we try common names.
DMARC ties both together and tells receivers what to do with mail that fails the checks: just monitor (p=none), move it to spam (quarantine) or reject it (reject).
Additional records
MTA-STS and TLS-RPT make sure that email to your domain is only delivered encrypted and send reports about problems. BIMI can display your brand logo next to your emails in some mailboxes.
Frequently asked questions
Is SPF enough on its own?
No. SPF only checks the technical sender, which recipients usually never see. Only DMARC protects the visible sender address – and only if the policy is set to “quarantine” or “reject”.
Where can I find my DKIM selector?
Open an email you sent in source view and look for the “DKIM-Signature” line. The value after s= is the selector.
How do I change the records?
All of these are TXT records in your domain’s DNS. They are maintained wherever your name servers are managed – for 1blu business GmbH domains in the domain and DNS interface or by our support team.
Domains and DNS in good hands
1blu business GmbH looks after domains, DNS and mail servers for companies, agencies and resellers – with dedicated contacts instead of a call centre.