Gmail not forwarding all mail… yes it is
It seems Gmail’s forwarding feature does not really forward all mail (true for Apps at least). When you select “Settings->Forwarding and POP/IMAP->Forward a copy of incoming mail to” and set an e-mail there, only the e-mails sent to your literal address (“user@somewhere”) are forwarded. E-mails that were already forwarded to that address or sent with the ‘+’ suffix (eg. “user+tag@somewhere”) are *not* forwarded. You can’t even use filters to achieve this.
This sucks, because when using Apps and regular gmail account you most likely would want to forward a couple of aliases (eg. webmaster) to the main account@domain and then all coming to that to regular gmail. And you can’t use the ‘+’ suffix for the real address. 
Update: Okay, I was too hasty. Looks like the above holds true only for when you send e-mail from your regular gmail account to the Apps one. When sent externally, all mail seems to be forwarded regardless of whether ‘+’ suffix is used or whether it’s sent to the actual account (“user+tag”, “webmaster+tag”, etc. are forwarded).
I don’t know about that. When I send externally it’s not forwarding either. Maybe it does it inconsistently
@Gabe
My Gmail in two of my accounts is not forwarding mail. This is a recent event. Is there a reason for this? Or a known bug tat anyone here may know about?
I’m also still a bit jumpy about gmail apps account forwarding. I have a google apps account from which I forward all mail to my private gmail account through forward function (not filters).
The thing I don’t want to happen is that gmail apps account filters spam because sometimes important mail can end up in spam and I don’t want to log in to my apps account just to check the spam folder. I will forget to do it anyway and my private gmail account filters incoming mail in the end anyway.
Do you know if there is a way to prevent gmail from filtering spam and forwarding really everything?
@vulfox
Good question. I haven’t tested this, but might be possible by creating a filter that matches all mail and prevents moving to spam (From: @, [x] Never send it to Spam) in the apps account.