Exchange 2007 and MAC users

Hello, I am curently strogeling here with a problem since a ocuple of days and I really hope you can help. We have exchange 2007 here with all PC windows XP and W7 clients but one user that is using a MAC. The email size limit for the entire company is 25MB sned/receive. Everything works perfectly for everyone but the MAC user. This user is using Office for MAC. This guys and only him can't send email bigger than 10Mb. I ensure Hubtransport and receiving connectors was set correctly and I also:

Modify those files for IIS:
Web.config entry–> <httpRuntime maxRequestLength=”25000” />
Web.config entry–> <requestLimits maxAllowedContentLength=”25000000“ />
 
In those locations:
C:\Program Files\Microsoft\Exchange Server\ClientAccess\Owa
C:\Program Files\Microsoft\Exchange Server\ClientAccess\exchweb\ews
C:\Program Files\Microsoft\Exchange Server\ClientAccess\Sync
 
And setting up these:
- appcmd set config “Default Web Site/ews” -section:requestFiltering -requestLimits.maxAllowedContentLength:25000000

- appcmd set config “Default Web Site/owa” -section:requestFiltering -requestLimits.maxAllowedContentLength:25000000

- appcmd set config “Default Web Site/Microsoft-Server-Activesync” -section:requestFiltering -requestLimits.maxAllowedContentLength:25000000

Then I sync up my edge and restart both servers.
My MAC user still can't send email over 10MB. Can any one give me and other clue or ideas? that would be very usefull especially because this MAC user is our CEO ... Ofcourse.

Thanks in advance!