A 550 or 554 bounce starts with your own domain. Your domain has settings that prove an email came from you, and when an email fails those checks, a third setting tells Gmail, Yahoo and AOL what to do with it.
When that third setting is set to reject, every email that fails the check bounces back to you with a 550 or 554 error. Fix the settings and the bouncing stops, usually within an hour.
The 3 email settings behind a DMARC bounce
Every domain that sends email can publish 3 settings. They live in your domain's DNS, the behind-the-scenes records that tell the internet where your website and email live. If your domain is registered with GoDaddy, that's usually where they are.
- SPF is a list of the servers allowed to send email for your domain. If Google sends your email and Google isn't on the list, the email fails.
- DKIM is a digital signature added to each email you send. Google Workspace doesn't add it for your own domain until someone turns it on.
- DMARC is the instruction for what happens when SPF and DKIM fail.
p=nonemeans deliver anyway.p=quarantinemeans send it to spam.p=rejectmeans bounce it.
What the 550 5.7.26 and 554 5.7.9 errors mean
| Error | Who sends it | What it means |
|---|---|---|
| 550 5.7.26 Unauthenticated email | Gmail | Your email failed your domain's checks, and your domain's DMARC policy says to reject it |
| 554 5.7.9 Failed authentication checks | Yahoo and AOL | The same problem, reported by a different provider |
Both errors point back at the sender's own domain. The person you emailed didn't block you, and their inbox isn't the problem.
Why a DMARC bounce can start when nobody changed anything
I recently fixed this for a local medical practice whose email suddenly started bouncing. Nobody at the office had touched a setting. The cause is one I see often on GoDaddy domains that use Google Workspace for email:
- The SPF record lists GoDaddy's servers but not Google's, even though Google Workspace sends all of the email.
- No Google DKIM signature is set up.
- The DMARC record is set to
p=reject, with a reporting address belonging to GoDaddy.
In that setup, the email has been failing SPF and DKIM for a long time. Without a strict DMARC policy, Gmail and AOL deliver it anyway. Once the DMARC record says reject, everything bounces.
GoDaddy now adds a DMARC record with a quarantine policy to domains purchased or transferred to GoDaddy (dmarcian, September 2025). If your DMARC record has a reporting address ending in onsecureserver.net, GoDaddy set it.
Stopping the bouncing usually takes changing 2 records.
How to fix DMARC bounces on a GoDaddy domain using Google Workspace
These steps are for the most common setup I see: the domain is registered at GoDaddy and email runs through Google Workspace. Screenshot every DNS record before you change anything. That's your undo.
- Change DMARC to stop the bouncing. Find the TXT record named
_dmarcand changep=rejecttop=none. Leave the rest of the record alone. This usually takes effect within about an hour. - Add Google to your SPF record. Find the TXT record on
@that starts withv=spf1and addinclude:_spf.google.com. If GoDaddy also sends or forwards mail for you, keepinclude:secureserver.netin the same record. A domain should only ever have 1 SPF record. - Turn on DKIM in Google Workspace. In the Google Admin console, go to Apps, Google Workspace, Gmail, Authenticate email. Generate a key, add it in GoDaddy as a TXT record named
google._domainkey, then click Start authentication. - Test it. Send an email to a Gmail address, open it, click the 3 dots, and choose Show original. SPF, DKIM and DMARC should all say PASS.
- Tighten DMARC again later. After a week or two of passing tests, change
p=nonetop=quarantine. Check back in a few days to make sure it wasn't changed again.
For a GoDaddy domain that sends through Google, a working SPF record often looks like this:
v=spf1 a mx include:_spf.google.com include:secureserver.net ~allWhy "mx" in a GoDaddy SPF record doesn't cover Google
Many GoDaddy SPF records include a mx. The mx part approves only the servers that receive your mail. Google sends your outgoing mail from a different set of servers. Without include:_spf.google.com, outgoing Google mail still fails SPF.
Why Gmail and Yahoo check this so closely now
Since February 2024, Google has required anyone sending email to personal Gmail accounts to set up SPF or DKIM (Google Workspace Admin Help, Email sender guidelines). Yahoo announced similar requirements at the same time. Domains that never set these up worked fine for years and are now one DMARC change away from bouncing.
Summary
- 550 5.7.26 (Gmail) and 554 5.7.9 (Yahoo and AOL) mean your own domain's DMARC policy is rejecting your mail.
- On GoDaddy domains using Google Workspace, the usual cause is an SPF record missing Google and no DKIM signature.
- It can start suddenly when a DMARC record gets added or set to reject, including by GoDaddy.
- Changing DMARC to
p=nonestops the bouncing. Fixing SPF and DKIM fixes the cause.
Sources: Google Workspace Admin Help, "Email sender guidelines." Google Workspace Admin Help, "Set up DKIM." Yahoo Sender Hub, "SMTP error codes." dmarcian, "How to Publish a DMARC Record with GoDaddy," updated September 16, 2025. Spam Resource, "GoDaddy setting DMARC for new domains," September 2025.