I would think, purposely moving to different areas would make it the most difficult to stay connected with your mail.
And since about the only thing you'd need mail for would be bills, then possibly by using an "on-line bank" you could eliminate the need for regular mail. I believe you can arrange to have most of your cummincations in that vein connect with you via the internet and e-mail...which you can get a hotmail or yahoo e-mail account.
Of course, then you'd need ot be diligent and get access to the internet on a regular basis. But pretty much all other things (magazines etc you'd have to just pick up at the store ...though some publications do have a way to subscribe on-line.
In my mind, clearly, planning ahead would be most beneficial as would educating yourself on how to maintain your connectino to the 'net in whatever area(s) you might chose to travel too.
Truck Stops are an obvious location (showers, food, internet etc) but the farther off the beaten path you are the less viable that option would become.
Should you go this way ...the vagabond route ... it would be interesting to follow your adventures and hear about the challenges.
Good Luck.