Bounce codes › Gmail
550 5.7.1: This message is likely unsolicited mail
Gmail read the message, decided it is spam, and refused it. The address you wrote to is fine.
Fix your sending setup Blocked or slowed down as possible spam
Gmail treated the message as spam and refused it.
- Sent by: Gmail / Google Workspace
- Permanent (hard bounce). Sending the same message again fails again.
How Gmail words it (source):
This message is likely unsolicited email. To reduce the amount of spam sent to Gmail, this message has been blocked.
Why it happens
- Low reputation of your sending domain or IP at Gmail.
- Recipients marked your earlier mail as spam.
- Content or links that match known spam.
- Mail to people who never asked for it.
What to do
- Do not resend the same message.
- Check that SPF, DKIM and DMARC pass with the SPF, DMARC and DKIM checker.
- Send only to people who signed up, and make unsubscribing one click.
- Google Postmaster Tools (free) shows the spam rate Gmail sees for your domain.
Don't confuse it with
Gmail uses 550 5.7.1 for more than spam: a rule set by the recipient's administrator, a missing Message-ID header, a second From header. The sentence after the code tells you which. Paste it into the bounce code lookup.
Questions
Should I remove the address?
Not for this bounce alone. The address exists.
Is 5.7.1 always spam?
No. In the standard it only means "delivery not authorized". Each mail server uses it for its own policy blocks.
Got a different bounce?
Paste the whole message into the bounce code lookup. It reads the code and the words and tells you whose move it is.
Related codes
421 4.7.0Temporarily rate limited: low reputation of the sending IP (Gmail)550 5.7.26This email has been blocked because the sender is unauthenticated (Gmail)550 5.7.511Access denied, banned sender (Microsoft 365)