There is a large number of Single-Board-Computers. The Pi happens to be well known. But each of these machines were done with some task in mind, so they have different design decisions ... The APU and ALIX line have mostly 3 ethernet interfaces, which is the stuff you want to have, if this box serves like a gateway of some sort. I have also used soekris.net boxes.
As for the Pi, I have a few complaints:
But I disgress. The Pi is a fascinating machine, it's just not the answer to all problems computing :-)
Email. Well, I do host an instance of dovecot/postfix. dovecot serves my several email boxes on the local network. However, it is not contacted directly. My official mailboxes are still hosted at some provider, I just download their content periodically using old and trusty fetchmail. For a nomadic setup this is not really good. Accessing home via TOR is possible but slow. You don't want to "work" with this. But you can then start any other tunnel/VPN solution from the "inside'. I do use this like once in a year. So, for me, this is good enough.
~bartender? All this techno-babbling makes my mouth dry ... how about another stout? Same as before? Yes? Ah, good. Thanks so much.
Cheers!