Set Maximum Message size in Exchange 2007

Open "Exchange Management Shell" from programs menu.

Firstly type ,

get-receiveconnector select identity,maxmessagesize to check message sizes.

then execute ;

set-receiveconnector "Connector Name" -maxmessagesize 5MB to change maximum size

Client Receive connectors are used to receive e-mail from users of Microsoft Exchange. This connector will be configured to only accept client submissions from authenticated Microsoft Exchange users.