\address ¶Synopsis:
\address{senders address}
Specify the return address, as it appears on the letter and on the
envelope. Separate multiple lines in senders address with a
double backslash, \\.
Because it can apply to multiple letters this declaration is often put
in the preamble. However, it can go anywhere, including inside an
individual letter environment.
This command is optional: if you do not use it then the letter is
formatted with some blank space on top, for copying onto pre-printed
letterhead paper. If you do use the \address declaration then it
is formatted as a personal letter.
Here is an example.
\address{Stephen Maturin \\
The Grapes of the Savoy}