What a flag means
A flag files the message under a label in your Gmail and moves it out of your way. Nothing is deleted, ever: open the Solicitor or Malicious label at any time to see exactly what was filed, and your dashboard shows the checks behind each decision.
A flag can be a mistake. Forwarded mail, misconfigured newsletters, and legitimate services with sloppy email setups can trip the same wires real attacks do. Sieve is built to be careful, and mail from people you know is trusted first, but when a wrong call happens it is always visible and always reversible.
When Sieve isn't sure
Some mail is neither clearly safe nor clearly dangerous. A common example is a sign-in or verification link you were not expecting: perfectly normal if you just signed up for that service, worth a careful look if you did not. Sieve calls this mail uncertain.
Uncertain is not a flag. The message stays in your inbox, and nothing is labeled or moved. Sieve may add a short caution note to the conversation in Gmail: a quiet reminder to check before you click, visible when you open the thread.
Uncertain is not a verdict. Your mail stays put, and the question is yours: did you expect this email?
Corrections
If a message was flagged by mistake, move it back. Drag it from the Solicitor or Malicious label to your Inbox in Gmail, or restore it from the dashboard. That single action puts the message back where it belongs and records a correction.
Corrections adjust your own filter. Sieve looks at what led to the wrong call and changes how your filter treats that sender, so future mail from them lands where you expect. No rules to write.
Want a specific email explained?
Every flagged message in your dashboard shows the checks behind its decision. If something still does not add up, email support@getsieve.io with the sender and the rough date. That reaches a person, and we never need the message body itself.