Gmail has all sorts of bugs or had. I had used to get a lot of email addressed to someone else. These were genuine email - when I forwarded them to the intended

Gmail has all sorts of bugs or had. I had used to get a lot of email addressed to someone else. These were genuine email - when I forwarded them to the intended recipient (basically resend to the "to" address) I got responses from people thinking I am a hacker or being stunned why would I get their email. After that I decided to just ignore those emails, especially that I haven't got response from Google. These had in common that they didn't use gmail domain. It was long time ago and I don't think I got any of those recently.