I have a transport rule to block messages that are larger than 25MB. I have it setup to send an incident report when ever that occurs. I realized that messages that were smaller than 25MB (eg 19MB or 20MB) were hitting this rule and getting rejected. I looked that the properties of the original message and outlook showed that the total size was smaller than 25MB.
I did some testing and was finally able to send a message of 24MB by setting the restriction to 33MB.
Any idea why my rule isnt working correctly and requires the restricted size to be 9MB larger than the message actually is? I even tried creating a new rule but got the same issue. And I know it's that rule that is blocking the message because if I disable it, I am able to send my message which was 24MB in size.