
This gets round both the forward/blacklist problem, and the single-point-of-failure problem. Since you mention that you want to forward your entire domain ( I'd strongly recommend that you investigate pointing your MX records at google.

I don't have a pointer to it, but I've done the MX end of things for more than one client in the past. Google does have a procedure for allowing you to point the MX records for your domain to the google mail servers, and have all that mail end up in your gmail account effectively, google hosts the domain for mail purposes. In addition, you're right that nothing in the SMTP protocol allows a relay to in some way disclaim responsibility for transmitted content ("Hey, I'm just a relay.") - if it did, every spammer would use it, too.

Clicking Learn more shows in part: Please note: When you create a filter to forward messages, only new messages will be affected. However, it did not work and the dialog does warn: Learn more. If your little hosted box goes down, your flow of inbound email stops. I tried to create a filter to forward in Gmail and selected the Also apply filter to 37 matching conversations. Secondarily, even if you can get this working fine, you've introduced an un-needed single point of failure into your email chain. If you're forwarding with SRS, this problem goes away (but getting SRS working can be non-trivial).
#Mail forward gmail how to
If you just do simple forwarding, and google makes any kind of reception / spam filtering / blacklist decision based on SPF, you'll break mail from every sender who advertises an SPF record ending -all (which is anyone who actually knows how to use SPF see eg Should SPF records provided by ISPs contain "all" at the end? and the comments). As is so often the case, the answer is "it depends".
