You are getting errors like this:
The message exceeds the maximum supported size.
There are some settings which limits the maximum message size in Exchange, which you have to change in order to process messages larger than the current maximum.
Lösung: If you like to process these messages by ExMixedFolders or EEAttachments you should use the following settings.
Show current settings
Get-ReceiveConnector | Format-List -Property Identity, MaxMessageSize
Get-TransportConfig | Format-List -Property MaxReceiveSize, MaxSendSize
Get-SendConnector | Format-List -Property Identity, MaxMessageSize
Get-SendConnector | Set-SendConnector -MaxMessageSize 100MB
Get-ReceiveConnector | Set-ReceiveConnector -MaxMessageSize 100MB
Set-TransportConfig -MaxReceiveSize 100MB -MaxSendSize 100MB
There are IIS settings as well
The settings for IIS are in the web.config.
- Open the file [ExchangeInstallation]\ClientAccess\exchweb\ews\web.config.
- Search for settings like maxAllowedContentLength and maxReceivedMessageSize .
- Change the values. The settings maxAllowedContentLength and maxReceivedMessageSize in the section UMLegacyMessageEncoderSoap11Element must not been changed.
- Save it and restart IIS.
Here you can find the Microsoft description for this problem.
The same settings are in Office 365, but it's not changeable here.