An invoice you sent a client goes unanswered, and then it turns out the email went to spam. The most common reason is that email authentication isn't set up on your domain. The good news: it's a one-off setup that usually takes less than an hour.
What has changed?
Since 2024 Gmail and Yahoo, and since 2025 Microsoft Outlook, have made SPF, DKIM and DMARC records mandatory for bulk senders. Even for companies that send few emails, missing these records raises the risk of messages being treated as untrustworthy.
SPF
Sender Policy Framework is a DNS record listing which servers may send email on behalf of your domain. For example, if you send both from your hosting server and through Yandex or Google mail, both must be in the SPF record. Example: v=spf1 include:_spf.google.com ~all.
DKIM
DomainKeys Identified Mail is a digital signature added to every email. The receiving server checks it against a key in your domain's DNS and confirms the message wasn't changed in transit. Your email service creates the DKIM key, and you add it to DNS.
DMARC
DMARC tells the receiving server what to do with emails that fail the SPF or DKIM check: nothing (none), send to spam (quarantine) or reject (reject). It's recommended to start with p=none, watch the reports, and then tighten the policy. Example: v=DMARC1; p=none; rua=mailto:[email protected].
How do the three work together?
SPF answers "is this server allowed to send?", and DKIM "has the message been changed?". DMARC matches the results of those two checks against the domain in the "From" field and says what to do. Together, they both improve delivery of your emails and make it harder for fraudsters to send fake emails in your domain's name.
How do I check?
Send yourself an email at a Gmail address, open it and choose "Show original". You should see PASS for SPF, DKIM and DMARC. If you see FAIL or NONE, the relevant record is either missing or wrong.
The most common mistakes
- Two separate SPF records for one domain — both are treated as invalid and must be merged into one;
- The site's contact form sending emails from a server that isn't in SPF;
- Old records left behind after switching email service;
- Starting DMARC straight at reject — badly configured sending suddenly disappears.
More tips
- Always include an unsubscribe link in bulk mailings;
- Remove undeliverable addresses from your list promptly;
- Using a separate subdomain for marketing mail (for example, news.company.az) protects the main domain's reputation.
If your domain is with us and you need help setting up these records, open a support request from your client account. More: Tips to keep your emails out of spam folders.
