Most hotel internet connections use an outbound SMTP proxy to store and forward email.
I’m never happy with that – it means that my mail could be delayed/lost/corrupted/tampered with/read on the way.
[Note: I know – SMTP is SMTP – it’s not secure; it’s like writing a postcard – but if I can avoid that proxy – it’s one less set of eyes..]
I’ve now configured Thunderbird to connect to a high port that’s NATted back down to port 25; I’ve also forced TLS to the mail server.
In theory that should keep my outbound mail (or really internal mail that only sits on my web server) a bit safer.