A Gmail warning that a message may not be from its apparent sender means you should verify the message before acting. An authentication failure can affect legitimate mail, especially through forwarding or mailing lists, but a recognizable name or logo is not enough to override the warning.
Pause the requested action
Do not open attachments, scan an emailed QR code, enter a password, or send money while the sender is uncertain. Read the visible request without interacting with its links. Note the claimed organization, full sender address, and any unusual urgency.
Open the relevant service independently. For example, check an account notice by typing the service’s known address or using its installed app. Contact a colleague using an existing directory entry, not the new phone number supplied in the suspicious email.
Inspect the individual message
- Expand the sender details for the specific message, not just the conversation’s latest reply.
- Compare the From address with Mailed-by and Signed-by where available.
- If your administrator needs evidence, use More, then Show original, and share the necessary headers through an approved private channel.
A question-mark indicator can mean Gmail could not authenticate the sender. Conversely, passing SPF or DKIM does not make every authenticated email trustworthy. A lookalike domain can have valid authentication of its own.
Choose reporting or sender-side repair
If the message is deceptive, use the message menu’s Report phishing option. If it is expected business mail, ask the verified sender to involve their mail administrator. The sender may need to repair authentication or a forwarding arrangement; the recipient should not disable security protections.
Do not create a Never send it to Spam rule for an entire company domain as a shortcut. That rule cannot establish identity, and an overly broad exception can admit other unwanted mail. If you already disclosed credentials, secure the affected account immediately through its official security settings and report the exposure.
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References
Reviewed against the linked product guidance, standards, and identified vendor or public-authority guidance on October 29, 2026. Available options and screen labels can vary by account, device, region, and organization policy.