On the contrary: it's a decent filter for folks who would be very unlikely to be able to follow the instructions to set up and maintain their end of the tunnel.

(It also happens to be a fantastic filter for spammers and other abusers. Is it perfect? Hell no. But it is very good.)

Gmail rejects mailing list messages that every other email provider accepts. It is impossible to get a human at Google to look at these issues. That's kinda the worst of all worlds. At least other email providing companies have support teams that can be talked to when things go off the rails.

I can setup email on my own domain, but I don't want to. It isn't worth my time or money. This doesn't mean that I can't follow tunnel broker instructions.