Like any web service, you may encounter a bug or an error while using Gmail. Google continuously monitor new reported bugs and errors all the time and work on respective fixes. If you come across error while using Gmail, you can always report it to Google for quick response and resolution of the issue.
Steps for reporting Gmail bugs, errors & issues
1. Disable Gmail labs and try to re-create error after disabling labs feature in your Gmail account. Goto Settings > Labs to turn off Labs in Gmail. If the issue presists, report it to Gmail support (step 3).
2. Check if that issue is on known issues page. If the issue is already listed, you can follow up resolution on the support page without having to report it again.
3. Use Report Gmail bug contact page on Gmail support. Provide your contact details and describe issue at hand for Gmail support.
Use ‘Report a bug’ button in Gmail
You can click ‘report a bug’ button at top right of your Gmail inbox to get going with error reporting. If you do not have ‘report a bug’ button in your Gmail inbox, click here to request for that feature in your Gmail account.