%windir%\system32\inetsrv\appcmd.exe set config "Exchange Back End/Microsoft-Server-ActiveSync/" -section:system.webServer/security/requestFiltering /requestLimits.maxAllowedContentLength:69730304 %windir%\system32\inetsrv\appcmd.exe set config "Default Web Site/Microsoft-Server-ActiveSync/" -section:system.web/httpRuntime /maxRequestLength:68096 %windir%\system32\inetsrv\appcmd.exe set config "Default Web Site/Microsoft-Server-ActiveSync/" -section:system.webServer/security/requestFiltering /requestLimits.maxAllowedContentLength:69730304 You have to run these commands from an administrative CMD. Without the Base64 overhead, this values allow messages sizes up to 50 MB. You can use the commands below to change the limit. In this case, my customer and I only changed the Active Sync limit.
#How to check outlook attachment size limit how to#
How to change client-specific message size limits? A 10 MB mail stuck in the outbox, a 6 MB mail was sent. My customer and I were able to proof this assumption. Taking the 33% Base64 overhead into account, the message size limit is ~ 6,5 MB. This is a server limit which can’t configured using the Exchange Admin Center. The message size limit for Active Sync is 10 MB ( Source). For example, if you specify a maximum message size value of 64 MB, you can expect a realistic maximum message size of approximately 48 MB. Base64 encoding increases the size of the message by approximately 33%, so the value you specify should be approximately 33% larger than the actual message size you want enforced. This accounts for the Base64 encoding of attachments and other binary data.
Especially this statement caught our attention:įor any message size limit, you need to set a value that’s larger than the actual size you want enforced. Instead, a quick search directed us towards the client-specific message size limits.
The cross-check with Outlook Web Access indicated, that the issue was not a configured limit on one of the Exchange connectors. How can I be notified when one of my users has an email sent to them that is rejected due to exceeding one of our Exchange 2010 message size limits? If I had seen the rejection when it occurred, we might have had enough time to solve the problem before our opportunity slipped away.Geralt / / Creative Commons CC0 (The email went out to a pool of potential customers bidding on a new contract, and presumably as long as he did his job by sending the email out, he might not care if it arrived successfully or not.) Evidently the government POC should have gotten an NDR (at some point) when his email was rejected by our system, but he either didn't get it in a timely manner, didn't notice it, didn't understand it, or didn't care. I checked our Exchange message tracking logs and confirmed that the email had in fact been sent but had been rejected for exceeding the maximum message size limit (the attachment was evidently pretty big).īy the time we realized what had happened, the government POC was gone for the day and the window of opportunity had closed. Late in the day they sent an email to that contact saying "where's that email?" The government POC replied saying, "I already sent it this morning at 11:00 AM." Yesterday one of my users was expecting an important, time-sensitive email from a government contact but never received it.