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.
{ via Blogoscoped Forum }