Hello Folks!!!, Hope you can help with this incident. We have an Exchange Server 2013 installed in a Windows Server 2012 R2, the mailflow it's working fine, BUT, in the past 2 days, I've detected that my organization cant' send mail to specifics external domains, lets say Domain ABC.external, and Domian XYZ.external, two different domains.
Never the less, We can send to other external domains.
The only thing that I can distiguish from those domains is that both are in Office 365.
Hope you can help me in this!!
Luis Antonio Navarrete Aranda Consultor Senior Akros Solutions Ecuador