If you wanted a way to bypass Gmail‘s spam filter, now it’s possible. Just create a filter that describes the cases when Gmail should not flag the incoming messages as spam and then check “Never send it to spam”. To bypass the filter for all the messages flagged as spam, type label:spam in the “Has the words” input box.
I intended to use the new option for my secondary Gmail accounts that automatically forward messages to my main account, but it doesn’t seem to work. Until now, the spam messages were not forwarded and I didn’t receive many important messages that were mistakenly flagged as spam. Since I can’t bypass the spam filter and forward the messages to a different account, another idea would be to use Gmail’s mail fetcher for my main account and download the messages from the secondary accounts.
There’s one situation that doesn’t require to set up a filter: if the messages from certain senders are constantly flagged as spam and they shouldn’t be, just add them to your contacts list.
copied from : here