SPF, DKIM and DMARC explained simply, plus the everyday habits that keep your emails out of your customers’ junk folders.
Few things are more frustrating than a quote or an invoice that your customer never sees because it went straight to spam. The good news is that most delivery problems come down to a handful of settings you can fix in an afternoon.
Why it happens
Every day, criminals send millions of emails that pretend to come from real businesses. To protect their users, Gmail, Outlook and other providers check whether an email really comes from the domain it claims. If they cannot tell, your genuine email looks just like a fake one.
The three records that prove it is really you
SPF
An SPF record lists the servers allowed to send email for your domain. If you also send email through other services, such as a newsletter tool or your accounting software, they must be in the same SPF record. A domain should only ever have one.
DKIM
DKIM adds a digital signature to every email you send. The receiving server checks the signature against a key in your DNS, which proves the email was not changed on the way.
DMARC
DMARC tells receiving servers what to do with email that fails SPF and DKIM, and can send you reports about who is sending email in your name. Start with a policy of none, which only reports, and tighten it once you are sure all your genuine email passes.
Major providers increasingly expect all three. Our guide SPF, DKIM and DMARC explained shows how to set them up for your Twerple email.
Everyday habits that help
- Send from your own domain. An invoice from
accounts@yourbusiness.comis trusted far more than one from a free webmail address. - Keep your lists clean. Remove addresses that bounce, and only email people who asked to hear from you.
- Write like a person. Avoid all-capital subject lines, a wall of links or a single large image with no text.
- Do not send bulk mail from your mailbox. Use a proper newsletter service for marketing email, and add it to your SPF and DKIM.
- Protect your passwords. A hacked mailbox sending spam can damage your domain’s reputation for weeks.
Still going to spam?
Our guide Emails going to spam: how to improve delivery covers the checks we would run, and our team is happy to look at your settings with you.