Hello!
We have 5 exchange servers in total. 3 on production site (1 cas , 2 mbox) and 2 on disaster site (1 cas , 1 mbox). Mailbox servers are on Database Availability Group. Today i had a very strange incident. Users they were complaining that they are getting some delivery delay messages. I opened the exchange toolbox and then went to queue viewer. I found inside more than 3500 emails from addresses like merandomnumber@myhouse.com. Could you please let me know what is wrong with our exchange configuration and it allows for someone to send an email from our mail servers
Thank you