How to keep your newsletter out of the spam filter

When a mail server receives your newsletter, it has a split second to decide one thing: is the sender really who the “From” field says it is? If it cannot answer yes, the message goes to spam — however good the content is.

Three records in your organisation’s DNS answer that question. You need all three, and the order matters.

SPF: who is allowed to send on your behalf

SPF is a list of the servers that are allowed to send mail from your domain. If you send through Ubivox, our servers have to be on that list — otherwise it looks to the recipient as though someone is impersonating you.

Note that a domain may only have one SPF record. If you already use Microsoft 365 or Google Workspace, Ubivox has to be added to the existing record, not put in a new one.

DKIM: a signature that cannot be forged

SPF says something about the sending server. DKIM says something about the message itself: every mailing gets a cryptographic signature that the recipient can verify against a key in your DNS.

DKIM is what keeps the message trustworthy even when it is forwarded — something SPF alone does not manage.

DMARC: your message to the outside world

DMARC ties the first two together and tells the recipient’s mail server what to do when the check fails: let the message through, put it in spam or reject it outright.

Always start at p=none. That changes nothing in practice, but you start receiving reports about who is sending in your name. Once the reports have been clean for a few weeks, you tighten to p=quarantine and then p=reject.

If you jump straight to p=reject, you risk blocking your own systems — the invoicing robot, the booking system, the intranet — because nobody realised they were sending mail too.

The order

  1. Fix SPF so Ubivox is included in the existing record
  2. Add the DKIM key
  3. Create DMARC with p=none and a reporting address
  4. Read the reports for a few weeks
  5. Tighten to p=quarantine, and then p=reject

The first three steps typically take your IT department a morning. Step four is the one people skip — and it is also where the problems tend to hide.

If you are unsure about your setup, we are happy to take a look. Write to support and we will run a check of the domain together with you.