Hi if a user adds a mail-filter (via ispconfig gui or roundcube plugin etc) the filter will match the "to" field. this doesn't work for example with mails where the user is in the BCC field, or with catch-all addresses etc. postfix adds the "X-Originating-To" header into the mail, so it would be better to match on that one and catch all the mails that are directed to the users address? greets KoS
Old thread, but fwiw, smtp/lmtp delivery agents do not add X-Originating-To, though it's apparently been added to the postfix wishlist (see http://postfix.1071664.n5.nabble.com/Tell-LMTP-who-is-original-recipient-td101488.html).
