Email authentication

How to fix emails going to spam

Inbox providers decide where your message goes using authentication, reputation and content. Fix them in that order — authentication problems are the most common and the easiest to fix.

Updated · Published by HostFaddy · 3 min read

Test your domain's email authentication

Free, no sign-up — results in seconds.

1. Fix authentication first

Run the Email Deliverability Checker. You want:

  • SPF — exactly one record, listing every service that sends as you, ending in ~all or -all. See SPF explained.
  • DKIM — enabled for your mailbox provider and every platform that sends as your domain. See DKIM explained.
  • DMARC — published, at least p=none, ideally progressing to quarantine or reject. See DMARC explained.
  • MX — present and correct, so replies and bounces can reach you.

2. Check your sending IP isn't blacklisted

Find the IP address your mail is sent from (in the Received headers of a message you sent) and check it with the Blacklist Checker. On shared hosting, another customer's behaviour can affect a shared IP — your host can help. See how to get delisted.

3. Make sure reverse DNS matches

The sending IP should have a PTR (reverse DNS) record pointing to a hostname, and that hostname should resolve back to the same IP. Many receivers penalise mail from IPs without proper reverse DNS. PTR records are set by whoever owns the IP — usually your host or ISP, not your DNS provider.

4. Look at what and how you send

  • Only email people who asked to hear from you. Purchased lists generate complaints and spam-trap hits.
  • Include a clear, working unsubscribe link in marketing email (Gmail and Yahoo require one-click unsubscribe for bulk senders).
  • Remove addresses that bounce.
  • Avoid image-only emails, link shorteners and misleading subject lines.
  • Send newsletters from a dedicated platform with its own DKIM set up for your domain, rather than from your normal mailbox.

5. Warm up new domains and IPs

A brand-new domain or server has no reputation. Start with small volumes to engaged recipients and increase gradually.

6. Ask recipients to help

Ask regular correspondents to mark your messages “Not spam” and add you to their contacts. That positive engagement feeds back into your reputation.

Frequently asked questions

Why do my emails go to spam in Gmail but not Outlook?

Each provider uses its own filters and reputation data. Gmail weighs authentication and engagement heavily. Check SPF, DKIM and DMARC first.

My SPF, DKIM and DMARC all pass — why is mail still going to spam?

Then look at reputation and content: blacklists, complaint rates, sending to old addresses, link reputation and how recipients engage with your mail.

Does a new domain go to spam more?

Often, yes. New domains have no reputation. Authenticate properly and build volume gradually.

If your mail server is on a shared IP with a poor reputation, a VPS from HostFaddy gives you a dedicated IP address you control.