anyone can tell me which command for increace attachment size on exchange 2007, actaully I've seached this forum, but still dont know how to do it, I am very pool the command in the management shell, so who can paste the command for increace user tom attachment up to 50M. thanks very much.

I believe the following link should help you. http://technet.microsoft.com/en-us/library/bb124345.aspx

thanks very much, but what command for change? this article make me headache, after read many times, still dont know how to change, can you simple give me the command ? thanks

There isn't a "single" command. There are multiple places that you need to check. The article explains each place message size limits can be set.

You have to have send and receive connectors in place first under your hub transports (under org and server). Once those are in place, you can do stuff like: get-receiveconnector connector name from hub transport | fl (lists the hub transport settings and valuesyou can't see from the gui. Works the same for get-sendconnector) Then usethe set-receiveconnector and set-sendconnector commands to set values. For instance, one of our send connectors is called "ToInternet", so I typed: get-sendconnector tointernet | fl One of the values (that the | fl shows) I need to modify was MaxMessageSize, so... set-sendconnector tointernet -maxmessagesize:20Mb Viola! I hope this helps.