Can't send more than 10M attachments on the Exchange 2010 phone?

One such problem these days, the mobile client of the Exchange 2010 messaging system cannot send more than 10MB of attachments.
Problem Description:

In an Exchange 2010 environment, message sinks and transmitter restrictions are set on 35m,windows Outlook can send large messages, but the phone cannot send or forward messages that are more than 10M.

Cause Analysis:

Phone-side Connection Exchange uses the ActiveSync protocol, which occurs because the ActiveSync default max Request length setting on the Exchange Server is 10MB. Mobile-side Connection Exchange uses the ActiveSync protocol, which is a bit different from Outlook sending messages on Windows computers.

Solution:

In an Exchange 2010 environment, this problem is more common when large attachments cannot be sent on iOS devices. Mobile-side Connection Exchange uses the ActiveSync protocol, which is a bit different from Outlook sending messages on Windows computers. In this case, event ID 1008 is generated on the Exchange Client Access server, as follows:

This problem occurs because the default Max Request length setting of ActiveSync on the Exchange Server is 10MB. When we send an attachment larger than 10MB, the iphone keeps trying to send it until the message leaves the device. To solve this problem, it is recommended that the maximum Request Length parameter in the Web. config for ActiveSync on the CAS server be set greater than 15MB. In general, higher than 50MB is not recommended, the normal setting is 15MB to 20MB. Because the message is too large, it can affect the efficiency of the message transfer. Please refer to the following steps:

1. On the Exchange CAS (Client Access server), locate the Clientaccess\sync\web.config file under the path where Exchange is installed. The default path is: C:\Program files\microsoft\exchange server\v14\clientaccess\sync.
2. Open the Web. config file, and then look for the
   3. Save the changed Web. config file.
   4. Restart IIS. Running IISReset in the Exchange Management shell
   5. Test if you can use your phone to send large attachments to messages.

Can't send more than 10M attachments on the Exchange 2010 phone?