We are running Exchange 2013 and have a problem where users are getting NDR reports when trying to send mail with a small attachment a Universal Distribution Group. The message received back is:
Delivery has failed to these recipients or groups:
_Group (_Group@mydomain.com)The recipient won't be able to receive this message because it's too large.The maximum message size that's allowed is 2 MB. This message is 3 MB
Why are messages to distribution groups capped at 2MB and how can I increase it to at least 10?