We are having a problem when using auto-reply feature.
When activating vacation/auto-reply all answered messages are sent as from=<> and our relay host are bouncing the mails.


Aug 3 11:52:02 sv811 postfix/smtpd[16739]: 3ED2537722B: client=sv807.example.com[]
Aug 3 11:52:02 sv811 postfix/cleanup[12800]: 3ED2537722B: message-id=<696838103.23921249293122169.JavaMail.root@sv80 9.example.com>
Aug 3 11:52:02 sv811 postfix/qmgr[8225]: 3ED2537722B: from=<>, size=1311, nrcpt=1 (queue active)
Aug 3 11:52:02 sv811 postfix/smtp[13367]: 3ED2537722B: to=<correo@example2.es>, relay=[]:25, delay=0.11, delays=0.04/0/0.05/0.02, dsn=5.0.0, status=bounced (host[] said: 550 Invalid IP ( for this domain (6) (in reply to MAIL FROM command))
Aug 3 11:52:02 sv811 postfix/qmgr[8225]: 3ED2537722B: removed