cf/README for sendmail 8.12.3

Eric Allman of the Sendmail Consortium

Miscellaneous Special Features

Plussed users

Sometimes it is convenient to merge configuration on a centralized mail machine, for example, to forward all root mail to a mail server. In this case it might be useful to be able to treat the root addresses as a class of addresses with subtle differences. You can do this using plussed users. For example, a client might include the alias:

root:  root+client1@server

On the server, this will match an alias for "root+client1". If that is not found, the alias "root+*" will be tried, then "root".