If you never interact with a gmail account, the spam filtering isn't going to work very well. It can't tell what you've read or skipped, and you never compose

If you never interact with a gmail account, the spam filtering isn't going to work very well. It can't tell what you've read or skipped, and you never compose anything, so it doesn't know who are your real correspondents. That's why forwarding in this way is a bad idea.