The browser (as should your email client) appears to have rejected those certs.

ok, so they have been rejected. Now what? I still would like to read my email... which is where VPN's come in handy.

I have had this situation in-flight a few times. I just used wireguard to a server I have. If I didn't already have that set up, I would have used an SSH+SOCKS tunnel to route around the damage. No need to send all my traffic to some shady VPN provider.

If you're running your own VPN, fine.

If you're using something like NordVPN, you're just swapping one shady outfit for another. Worse, in many cases.

Might be better to just wait until you land.