If your ISP account allows unlimited email user names, you may wish to arrange for sendmail to accept all incoming email and redirect mail for unknown users to a particular user such as postmaster. To do this, a few changes are needed to sendmail's configuration file. If you want to deliver mail for unknown users to some user other than postmaster , replace postmaster with the name of the user who should receive such mail. By default, postmaster is an alias for the real user root . I hope these instructions prove useful.
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