Gmail 535 5.7.80
Username and password not accepted
Gmail 535 5.7.80 means: username and password not accepted. It is a permanent failure, so do not retry it unchanged. Google rejected the credentials. Check them, and use an app password or OAuth if 2-Step Verification is on.
Gmail’s exact wording
Quoted from Google Workspace Admin Help: Gmail SMTP errors and codes, checked 2026-11-05. Placeholders are Gmail’s own.
Reply text
Username and Password not accepted. For more information, go to Can't sign in to your Google Account.
| Who sends it | Gmail and Google Workspace |
|---|---|
| Basic code | 535: Authentication credentials invalid (RFC) |
| Enhanced code | 5.7.80: Gmail-specific, not in the IANA registry. Its subject digit puts it under 5.7.0 other or undefined security status. |
| Permanent or temporary | Permanent (5xx) |
| Verifying the list prevents it | No |
In practice
Google rejected the username and password. Accounts with 2-Step Verification need an app password for SMTP clients that cannot use OAuth, and Workspace administrators can turn off less secure sign-in methods entirely. Check the credentials, then check which sign-in methods the account allows.
What the sender should do
Google rejected the credentials. Check them, and use an app password or OAuth if 2-Step Verification is on.
Would verifying the list have prevented Gmail 535 5.7.80?
No
This reply is about your sending setup, the message or the receiving system, not about whether the address exists, so verifying the list will not prevent it.
Common questions
- What does Gmail 535 5.7.80 mean?
- Gmail 535 5.7.80 means: username and password not accepted. It is a permanent failure, so do not retry it unchanged. Google rejected the credentials. Check them, and use an app password or OAuth if 2-Step Verification is on.
- Should I retry after Gmail 535 5.7.80?
- No. It is a permanent (5xx) failure, so the same message to the same address will fail again. Fix the cause first. Google rejected the credentials. Check them, and use an app password or OAuth if 2-Step Verification is on.
- Would verifying my list have prevented Gmail 535 5.7.80?
- No. This reply is about your sending setup, the message or the receiving system, not about whether the address exists, so verifying the list will not prevent it.
Sources
- Google Workspace Admin Help: Gmail SMTP errors and codes (checked 2026-11-05)
- RFC 4954: SMTP Service Extension for Authentication (checked 2026-11-05)
Registry and provider wording is quoted exactly; guidance is written by the SimpleVerifier Team.
SimpleVerifier Team · Last checked against the sources 2026-11-05