I'm running Fedora Core 3, Sendmail version 8.13.1 and vacation version 1.2.6.1-3. When I put "|/usr/bin/vacation user" and a /user in the .forward file the vacation program is recognized by sendmail and a copy of the received e-mail is put in the mailbox of the user. So far so good. When I send an e-mail for the first time form any sender, the sender gets a "I'm on vacation" message back. When I send an e-mail for the second time from the same sender the e-mail is copied to the mailbox, but the auto reply is not send. In the maillog nothings seems strange other then after the .forward file is read by sendmail, no follow up of replying to is done.
It looks like that the sender addresses are stored somewhere and called on by the vacation program. Also looked at the vacation.db file in the users dir and there the sender address is in. Removing the .db will not solve the problem. Or removing the address from the vacation.db. Only new and first time senders will get a reply. Pease Help!