Hello everyone, I have four Exchange Server 2010 Sp2 Rollup3, two servers are mailbox and are in DAG, others servers are CAS/HUB. The problem is with OOF, when I send a mail from to a external domain, for example gmail I recieve the return message from OOF, but if I send more messages from the same gmail sender to same internal Exchange recipient, the OOF message is not sent to gmail sender I thinks that Exchange sends only one OOF message per sender. Anyone has already gets this problem?