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Is there any possibility to redirect / discard email of unknown users instead of sending it back to the sender with a rejection message that user is unknown?

I don't want to use any milter for this purpose or any sender validation tool. Have sendmail ability into it to do this?

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up vote 1 down vote accepted

The sendmail option you want is called LUSER_RELAY. To send all mail addressed to unknown users to "unknown" on the local system, you would put this line in your mc file:


Once you have built a new file you will have a line that specifies the destination for all email addressed to unknown users:


To never deal with the email, put a .forward file in the target user's home:

| /dev/null

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