Tag Archive: outlook

Exchange comes with some default limits on attachment size and file types. this is for security as well as stability- without limits a user could send a 1 Gb movie to a distribution list, which would seriously hamper your server. I am typically good with defaults, but I am having an issue with Sharepoint. I can not seem to upload a 500Mb PowerPoint presentation. I tried upload from the site, I tried file copy in windows explorer. I then broke the file in half, and still can’t get it over. So I thought I would email it to my list- I do have several libraries mail enabled.

Exceed File Size

Exceed File Size

The file is 117 Mb. That is not too big for Outlook or Exchange, though it is for my Sharepoint. And yes, I changed the connection timeout and the file size limit in CentralAdmin- still got nothing.

To change the max attachment size in Exchange 2007, open up Exchange Management console. Expand Organization configuration and click on Hub Transport. Click on the Global Settings tab, and double-click Transport Settings. Change the first two values to what fits your needs. I changed mine to 1 Gb each- I will be changing them back after I send this file.

Transport Settings

Transport Settings

this can also be done in the Active directory.

Click Start>Run and type mmc.exe

Click file, add or remove snap-in.

Click ADSI Edit, and Add. Click Ok.

In the console that opens, right-click ADSI Edit, and click Connect to.

Select the radial button that says A Well Known Naming Context, and select Configuration.

Connect Configuration

Connect Configuration

Click Ok.

Expand Configuration>CN…>Services>Microsoft Exchange>first Organization>Global Settings>

Right click Message Delivery and select properties.

Change these attributes to manipulate the size values:

delivContLength – incoming message size limit (default is 10240)

submissionContLength – receiving message limit (default is 10240)

Message Delivery Properties

Message Delivery Properties

Close out everything you did, and go back to Outlook… Oh no! You STILL cant attach the file. Well if Exchange is not stopping you anymore, what is? Outlook itself?

Outlook 2010 restricts message size to 20 Mb. Lets change this as well.


Type regedit and click open.

Navigate to HKEY_CURRENT_USER\Software\Microsoft\Office\14.0\Outlook\Preferences

Right click the folder and select new DWord Value. Name the new key MaximumAttachmentSize.

Right click the new key, select decimal, and enter the size you want to increase it to. I used the same value I used in Exchange 2007, or 1024000.

Restart Outlook, attach away.

Remember, messing with the registry can brick your system. Backup first, and write down what you did so that if errors occur, you can reverse them easily.

There is one more setting that supposedly changes the way your site handles attachment size, which is done wy adding some code to the web.config file for one of your site’s pages. I will not get into it, as I did not do it. Google search for it and you will come up with a few sites.

You run the Exchange 2007 BPA and you get a warning for Disable MAPI Clients.

Disable MAPI Warning

Disable MAPI Warning

This warning is not a huge deal, as it has been present on my production Exchange server for months without causing issue. I HATE error messages though, and I am now getting around to getting rid of it.

You could go read the lengthy Technet article (linked here) or you could skip all the explanation and just fix it. Read on…

What this setting does is tells Exchange with versions of Outlook can connect to it. I have the pleasure of installing all of the office clients, so I know the lowest version of Outlook is 2007. I also know no one in the office connects to Exchange from Outlook at home (VPN or RPC over HTTPS) that is lower than 2007. So why would I let outdated clients such as 97, 98, 2000 or 2003 connect? I wouldn’t!

A list of client version numbers is here.

Warning: If you have older clients that connect using Outlook 2003 or 2k, you might not want to follow my advice.

Let’s see what sort of clients connect right now. Open up Exchange Management Shell. It will be in the Start Menu, under All Programs Exchange Server 2007.

Once it’s open, you need to navigate to the folder that has the scripts in it. Type in: cd “C:\Program Files\Microsoft\Exchange Server\Scripts” and hit enter (leave the quotation marks on). Now type get-logonstatistics



You get a long page, so lets put it in a text file to decipher by adding > c:\logon.txt. Reading the file tells us nothing, at least me anyhow. I blocked out the names to save identities.

So, I’ll look another way. Ill navigate to HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MSExchangeIS\ParametersSystem registry value in regedit and read the value for DisableMAPIClients.

Mine is set to 0.0.0-5.3164.0, which is the default. I would like to restrict everything before Outlook 2007. So, reading the Technet article leads me to this value:


Warning: Back up all changes to the registry before you make them. Save the file with the date on it. If you break your box, it’s not my fault- registry changes can be dangerous.

I notice though that my Exchange does not want me to block version 8.x.x. So I will change that value to the lowest in the 9x.x range there is, which gives me:


This is telling Exchange to block ALL MAPI Access from client up to Outlook 2007, including Outlook 2003 SP3, excludeing ESA and Outlook 2007, 2010. This excludes a few numbers between 5.x.x and 9.x.x. This is because the Exchange System Attendant components use these numbers, so do not restrict them. Ill paste that value in the registry key.



Close out regedit and see now what BPA warns you about:
 The message now reads:

Some versions of MAPI clients are blocked on server SOLACESERVER.solace.local. Verify that version ‘6.x.x.x’ and version ‘8.x.x.x’ clients are not blocked as the Microsoft Exchange System Attendant process uses these version identifiers for performing server functions. Current MAPI blocking setting: 0.0.0-5.65535.65535;9.0.2711-11.65535.65535.

Thats correct then, as our warned numbers are excluded. Safely hide this message from all instances. If you have client connection problems, you can change this value in the future.

%d bloggers like this: