But for important bank, government mail, I ghink a private maul box snd forwarding service like Mail Boxes Etc. would suffice. However, some banks may catch onto this and give notice closing your account.
My military pension also no problem with DOD Finance. Online access to my pay account is authenticated via email. Two of my credit cards from the U.S.A mainland also use email for entering 'code' to access my online accounts.
My pensions, Social Security and VA go into bank of Hawaii branch and two credit unions on Guam. Never a problem with online banking. Bank and the credit unions occassionally call my Thai mobile number for authentication when I attempt to log into my online accounts. And every few months, I contact the bank on skype or use my online access to notify of travel in Thailand or Philippines, or the U.S.A.