You can also look at "genericstable".
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The argument of FEATURE(`genericstable') may be the map definition; the default map definition is:
hash /etc/mail/genericstable
The key for this table is either the full address, the domain (with a leading @; the localpart is passed as first argument) or the unqualified username (tried in the order mentioned); the value is the new user address. If the new user address does not include a domain, it will be qualified in the standard manner, i.e., using $j or the masquerade name. Note that the address being looked up must be fully qualified. For local mail, it is necessary to use FEATURE(`always_add_domain') for the addresses to be qualified. The "+detail" of an address is passed as %1, so entries like
old+*@foo.org new+%1@example.com
gen+*@foo.org %1@example.com
and other forms are possible.
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