Flagging as spam is different. The OP is talking about rejecting it before it even gets to your inbox. If gmail is improperly flagging a message I get as spam

Flagging as spam is different. The OP is talking about rejecting it before it even gets to your inbox. If gmail is improperly flagging a message I get as spam, I can create a filter to never send it to spam. If they're rejecting it like the OP talks about, if I want to stay with gmail I have no way to get that email.