Set organization send connector

Set-SendConnector -Identity 'To Internet' -MaxMessageSize 20MB  # Limit for Internet email real size(15MB)

Set organization transport

Set-TransportConfig -MaxSendSize '40MB' -MaxReceiveSize '40MB'

Set receive connector

Set-ReceiveConnector -Identity 'MBX01\Anonymous01' -MaxMessageSize 40MB

If above setting is valid, must be restart 'Microsoft Exchange Information Store' service

Restart-Service MSExchangeIS

 

Configure client-specific message size limits from the command line (Run as Admin in CMD)

  1. ActiveSync

%windir%\system32\inetsrv\appcmd.exe set config "Default Web Site/Microsoft-Server-ActiveSync/" -section:system.webServer/security/requestFiltering /requestLimits.maxAllowedContentLength:41943040

%windir%\system32\inetsrv\appcmd.exe set config "Default Web Site/Microsoft-Server-ActiveSync/" -section:system.web/httpRuntime /maxRequestLength:40960

%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/Microsoft-Server-ActiveSync/" -section:system.webServer/security/requestFiltering /requestLimits.maxAllowedContentLength:41943040

%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/Microsoft-Server-ActiveSync/" -section:system.web/httpRuntime /maxRequestLength:40960

%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/Microsoft-Server-ActiveSync/" -section:appSettings /[key='MaxDocumentDataSize'].value:41943040

  1. OWA

%windir%\system32\inetsrv\appcmd.exe set config "Default Web Site/owa/" -section:system.webServer/security/requestFiltering /requestLimits.maxAllowedContentLength:41943040

%windir%\system32\inetsrv\appcmd.exe set config "Default Web Site/owa/" -section:system.web/httpRuntime /maxRequestLength:40960

%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/owa/" -section:system.webServer/security/requestFiltering /requestLimits.maxAllowedContentLength:41943040

%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/owa/" -section:system.web/httpRuntime /maxRequestLength:40960

%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/owa/" -section:system.serviceModel/bindings /webHttpBinding.[name='httpsBinding'].maxReceivedMessageSize:41943040

%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/owa/" -section:system.serviceModel/bindings /webHttpBinding.[name='httpBinding'].maxReceivedMessageSize:41943040

%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/owa/" -section:system.serviceModel/bindings /webHttpBinding.[name='httpsBinding'].readerQuotas.maxStringContentLength:41943040

%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/owa/" -section:system.serviceModel/bindings /webHttpBinding.[name='httpBinding'].readerQuotas.maxStringContentLength:41943040

3.EWS

%windir%\system32\inetsrv\appcmd.exe set config "Default Web Site/ews/" -section:system.webServer/security/requestFiltering /requestLimits.maxAllowedContentLength:67108864
%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/ews/" -section:system.webServer/security/requestFiltering /requestLimits.maxAllowedContentLength:67108864
%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/ews/" -section:system.serviceModel/bindings /customBinding.[name='EWSAnonymousHttpsBinding'].httpsTransport.maxReceivedMessageSize:67108864
%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/ews/" -section:system.serviceModel/bindings /customBinding.[name='EWSAnonymousHttpBinding'].httpTransport.maxReceivedMessageSize:67108864
%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/ews/" -section:system.serviceModel/bindings /customBinding.[name='EWSBasicHttpsBinding'].httpsTransport.maxReceivedMessageSize:67108864
%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/ews/" -section:system.serviceModel/bindings /customBinding.[name='EWSBasicHttpBinding'].httpTransport.maxReceivedMessageSize:67108864
%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/ews/" -section:system.serviceModel/bindings /customBinding.[name='EWSNegotiateHttpsBinding'].httpsTransport.maxReceivedMessageSize:67108864
%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/ews/" -section:system.serviceModel/bindings /customBinding.[name='EWSNegotiateHttpBinding'].httpTransport.maxReceivedMessageSize:67108864
%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/ews/" -section:system.serviceModel/bindings /customBinding.[name='EWSWSSecurityHttpsBinding'].httpsTransport.maxReceivedMessageSize:67108864
%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/ews/" -section:system.serviceModel/bindings /customBinding.[name='EWSWSSecurityHttpBinding'].httpTransport.maxReceivedMessageSize:67108864
%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/ews/" -section:system.serviceModel/bindings /customBinding.[name='EWSWSSecuritySymmetricKeyHttpsBinding'].httpsTransport.maxReceivedMessageSize:67108864
%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/ews/" -section:system.serviceModel/bindings /customBinding.[name='EWSWSSecuritySymmetricKeyHttpBinding'].httpTransport.maxReceivedMessageSize:67108864
%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/ews/" -section:system.serviceModel/bindings /customBinding.[name='EWSWSSecurityX509CertHttpsBinding'].httpsTransport.maxReceivedMessageSize:67108864
%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/ews/" -section:system.serviceModel/bindings /customBinding.[name='EWSWSSecurityX509CertHttpBinding'].httpTransport.maxReceivedMessageSize:67108864
%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/ews/" -section:system.serviceModel/bindings /webHttpBinding.[name='EWSStreamingNegotiateHttpsBinding'].maxReceivedMessageSize:67108864
%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/ews/" -section:system.serviceModel/bindings /webHttpBinding.[name='EWSStreamingNegotiateHttpBinding'].maxReceivedMessageSize:67108864

 

web service setting must be restart IIS service

net stop w3svc /y

net start w3svc

 

Reference link:

https://docs.microsoft.com/en-us/exchange/mail-flow/message-size-limits?view=exchserver-2016

https://docs.microsoft.com/en-us/Exchange/architecture/client-access/client-message-size-limits?view=exchserver-2016