Issue:
Max incoming / outgoing message size is too small
Solution:
Increase the limit of the incoming / outgoing message size.
Method:
1 – Open Exchange Command Shell (run as Administrator)
2 – To review:
–> Get-TransportConfig | ft MaxSendSize, MaxReceiveSize
3 – To change this:–MaxSendSize 20MB –MaxReceiveSize 20MB
–> Set-TransportConfig