Symptoms – User were reporting that emails from the domain ‘Gmail.com’ were being blocked by Mimecast.
Observations - Several users reported that these emails were being blocked. IT observed that Mimecast be rejecting the emails due to a domain block.
Resolution – We removed the global ‘gmail.com’ block from Mimecast and the emails were able to be sent again.
Root Cause Analysis – A user added the global block on the Mimecast client which resulted in the company not being able to get emails from that domain. According to Mimecast technicians there is no ability to trace who performed this block, but they showed us how to check for it in the future. An ITGlue article will be created for this resolution.