Hi all I have a number of Outlook 2011 (Outlook for MAC) users who are unable to send attachments that are much over 15MB. I have already set the relevant parameter within webconfig.ini so that up to 50mb can be sent. I have configured a handful of clients to connect directly to a test CAS of mine, and have managed to get a 16MB file sent successfully. but anything above tbis fails with 1 of the following: "HTTP error: The resource is not found" OR "Connection to the Server failed or was dropped" I have tried a number of things but none seem to have made a difference: 1)Changed MTU size on ethernet on the MAC. On Snow Leopard (10.6.6) the default is 1500, apparently Exchange can have a problem with this is it is not the 1492 default. 2)Tried a resend from within the Drafts folder (some people reported that they got this to work. After the email failed, it went into drafts). None of the above work for me. There are some notional postings on the web referring to an SSL\Handshaking timeout possibile within IIS on the CAS servers? Has anyone come across this or got any thoughts on what to try? Tom

Is this IIS7? Can you enable trace logging and send again, look at the logs to see if you can isolate if its an IIS restriction?James Chong MCITP | EA | EMA; MCSE | M+, S+ Security+, Project+, ITIL msexchangetips.blogspot.com

Does the user who can send the attachment with 16MB file also use Outlook 2011? Based on my research, please edited the file C:\Program Files\Microsoft\Exchange Server\V14\ClientAccess\ews\web.config and change the maxReceivedMessageSize value to 51200000 underneath the <EWSMessageEncoderSoap11Element />. Please assure to change in web.config for all the maxReceivedMessageSize to 51200000 and did IISRESET. Thanks. NovakPlease remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

Hi Novak The entry that my web.config has is "httpRuntime maxRequestLength", it isn't the "maxReceivedMessageSize" you are referring to. (I suspect you are Exchange 2010 yes?). Either way, I have got that value correctly set (100MB in our case) but it doesn't do the job. It also seems as if Entourarge 2008 EWS has reports of this behaviour....so it suggests an EWS issue and probably located within IIS7. Tom

Just for process of elimination are you able to send that large using OWA?James Chong MCITP | EA | EMA; MCSE | M+, S+ Security+, Project+, ITIL msexchangetips.blogspot.com

Have you changed your transportconfig? or at minimum the users maxsendize?

Try answered thread here. http://social.technet.microsoft.com/Forums/en/exchange2010/thread/958ba423-a069-4d29-afef-ebe5f986605a Solution: Increase the 'maxRequestLength' of web.config (found in 'ClientAccess\exchweb\ews' & 'ClientAccess\owa'). Increase the 'maxReceivedMessageSize' of web.config (found in 'ClientAccess\exchweb\ews'). Opened command prompt & run the following: cd \Windows\System32\inetsrv appcmd set config "Default Web Site/ews" -section:requestFiltering -requestLimits.maxAllowedContentLength:value appcmd set config "Default Web Site/owa" -section:requestFiltering -requestLimits.maxAllowedContentLength:value iisreset James Chong MCITP | EA | EMA; MCSE | M+, S+ Security+, Project+, ITIL msexchangetips.blogspot.com