[BlueOnyx:15730] the email alias, sys, is already in use on this system

[Tobias Gablunsky]

Hello,

I was sure this question was already asked a thousand times on this list, but I cannot find an answer to this special case:

A customer wants to set "sys" as an email alias to an existing user and gets the above message.

I searched through the alias files on the server and checked the files mentioned in the message log (/usr/sausalito/handlers/base/email/validate_alias.pl, /usr/sausalito/handlers/base/user/handle_user.pl).
I did find restricted names but I didn't find sys on one of those lists..

PS: I tried and searched on both 5208R-BETA1 and 5108.

Who can help?

Thanks.

Tobias