Yesterday at 7:30 pm I have an Exchange server I am in charge of that could no longer send emails to the outside and therefore no longer receive any. The internal emails were working. around midnight, the external emails started working again. i don't understand what happened. Which logs can i look at to understand this malfunction? Every avenue of investigation and understanding is welcome.
Version : Exchange server 2010 SP3
Windows Server 2008R2 SP1