In order to create virtusertable mappings, you must first create a text file in the /etc/mail/ directory of your
server (there is a sample file in that directory named virtusertable.sample). This file will contain virtusertable
mappings.
Each entry in a virtusertable should be on a single line. The original recipient address on the left hand side,
with one or more spaces or tabs separating it from the right hand side, which contains the destination address.
The original recipient is the E-mail address that people will send messages to, and can be either a full address
(username.name), or a catch all for all messages to the specified domain (.name). If you
want to create multiple virtusertable entries for a single domain, make sure that you put the catch all below any other
entries for that same domain name.
The destination address should be a local user, an alias, or a remote Email address. You may also use a %1 to
indicate that the original user should be prepended to a catch-all.
Any time you make a change to the /etc/mail/virtusertable text file, you will need to create a db file that
sendmail can read. The following command will create the /etc/mail/virtusertable.db file when run by
root.
# makemap hash /etc/mail/virtusertable < /etc/mail/virtusertable