Yes, you do need a return address on a business letter and it should include telephone or email information because:
No.
There is no rule against it, but as postcards are intended for use while travelling, there is no designated space for a return address.
You can get the change of address cards for free from your local post office. Fill the forms out and return them back to the same post office. In return your mail will be rerouted for a specific amount of time.
Yes, you should always put a return address on any envelope. The person you are sending the sympathy card may not know your last name or address and also the Postal Service needs to have a return address in case you put the wrong address down of the recipient.
A return address is used in case the envelope is not delivered.
yes
The return address is typically placed in the top-left corner of an envelope. This helps in case the mail cannot be delivered and needs to be returned to the sender.
you put the other persons address on the envelope and put your return address on the left corner of the envelope and put a stamp
The post office would return it to the return address.
The same reason that Americans put stamps on postcards. Too mail the postcard!
Just write return to sender on the front and put unknown not at this address.
The return address goes in the top-left corner of the envelope.
yes, maybe, i really dont know