Out of office is a server built-in rule that help the user notify all senders that he’s not in office.
When creating the rule via outlook or outlook web access, exchange 2007 enabling rules for internals and externals senders.
When sending email first time to recipient with Out of office rule enabled – the rule should work and the sender should get out of office auto reply.
When sending from same sender another email – there will be no reply since exchange is designed to save an unseen list inside the database of all senders. The rule examine if the sender is in the list. If the sender is in the list – I won’t send another “out of office” reply. If the sender isn’t there – it will send reply and insert the sender to that list.
How to delete the unseen list?
Simply disable-enable the rule in outlook or outlook web access or modify data in the rule like: changing time the rule will operate or change the text in the out reply message