Exchange ServerDefault mail size limits for various protocols in can directly impact your daily workflow and user experience. ActiveSync, Exchange Web Services (EWS) ve Outlook Web App (OWA) Different limits have been predetermined for the
These restrictions can be adjusted based on your organization's needs. EWS ve OWA limits for, Exchange Admin Center (EAC) or Exchange Management Shell (EMS) while it can be configured via, ActiveSync Configurations must be made directly via web.config files.
There is an important rule to consider when changing email sending limits in Exchange Server: Base64 encoding message size approx. %33 The message size limit you want to set must be larger than the size you specify.
Exchange Server Default Mail Sizes
Exchange Server Default Mail Size Limits:
- ActiveSync: 10MB by default
- EWS: 64 MB
- OWA: 35 MB
In the default configuration, if we take into account the Base33 encoding overhead of 64% of the message limit, the practical message limit can be calculated as 6.5 MB. This is calculated by the following formula:
Ekli dosya boyutu dahil mail boyutu + %33 = Toplam mail boyutu
Web.Config Settings for Exchange Server ActiveSync Limit Change
On Exchange Server ActiveSync to set limits, Client Access (frontend) and Backend services web.config
The changes that need to be made to the files should be as follows.
- Exchange Server'in ActiveSync To send and receive large emails using,
MaxAllowedContentLength
You need to configure the setting. This value determines the maximum content length that clients and the server can handle and is set to a certain limit by default. If 50 If you want to enable sending of emails that are MB or larger, you will need to increase this value.
maxAllowedContentLength
vemaxRequestLength
settings are important for managing large email sends and receives. These settings should be adjusted carefully because they can impact system resources.
Services | Configuration file | Keys and default values | Size |
---|---|---|---|
Client Access (frontend) | %ExchangeInstallPath%FrontEndHttpProxySyncweb.config | maxAllowedContentLength="30000000" (not present by default; see comments) | bytes |
Client Access (frontend) | %ExchangeInstallPath%FrontEndHttpProxySyncweb.config | maxRequestLength="10240" | kilobytes |
Back-end | %ExchangeInstallPath%ClientAccessSyncweb.config | maxAllowedContentLength="30000000 bytes" (not present by default; see comments) | bytes |
Back-end | %ExchangeInstallPath%ClientAccessSyncweb.config | maxRequestLength="10240" | kilobytes |
Back-end | %ExchangeInstallPath%ClientAccessSyncweb.config | <add key="MaxDocumentDataSize" value="10240000"> | bytes |
You must have Administrator privileges to change Web.Config.
Change Exchange Server ActiveSync Limit Using CMD
Setting size limits for ActiveSync in Exchange Server environments can be important for managing large email transfers.
Below is the IIS management tool appcmd.exe
There are commands that will modify ActiveSync Limits using . These commands set the maximum allowed content length and request size for ActiveSync. These settings may need to be reconfigured after each Exchange Cumulative Update (CU), as they may revert to default values after each Exchange Cumulative Update (CU).
The following commands, ActiveSync is used to configure the maximum allowed content size and maximum request size for the service. You can adjust the values according to the requirements of your environment:
%windir%system32inetsrvappcmd.exe set config "Default Web Site/Microsoft-Server-ActiveSync/" -section:system.webServer/security/requestFiltering /requestLimits.maxAllowedContentLength:69730304
%windir%system32inetsrvappcmd.exe set config "Default Web Site/Microsoft-Server-ActiveSync/" -section:system.web/httpRuntime /maxRequestLength:68096
%windir%system32inetsrvappcmd.exe set config "Exchange Back End/Microsoft-Server-ActiveSync/" -section:system.webServer/security/requestFiltering /requestLimits.maxAllowedContentLength:69730304
%windir%system32inetsrvappcmd.exe set config "Exchange Back End/Microsoft-Server-ActiveSync/" -section:system.web/httpRuntime /maxRequestLength:68096
%windir%system32inetsrvappcmd.exe set config "Exchange Back End/Microsoft-Server-ActiveSync/" -section:appSettings /[key='MaxDocumentDataSize'].value:69730304
- maxAllowedContentLength: HTTP Specifies the maximum size of requests in bytes. In the example it is set to 69,730,304 bytes (approximately 66.5 MB).
- maxRequestLength: HTTP Specifies the maximum size of requests in kilobytes. In the example, it is set to 68,096 KB (approximately 66.5 MB).
- MaxDocumentDataSize: ActiveSync Determines the maximum document size that can be synchronized with.
After Exchange Server updates (CU), the configuration settings are reverted to default values. Therefore, these scripts need to be run again after each update.