Microsoft Outlook Mac Desktop Won't Open

  1. Outlook Won't Open
  2. Outlook Won't Open Processing
  3. Microsoft Outlook 2010 Won't Open
  4. Microsoft Outlook Mac Desktop Won't Open Windows 10
  5. Microsoft Outlook Mac Desktop Won't Open Windows 7


Outlook Won't Open

Sep 02, 2015 Office 365 consumer subscribers can get the new Outlook for Mac by going to their My Account page. For people who already have Office for Mac 2011 and Outlook for Mac 2011 installed on their Mac, check out this help article for guidance. Outlook for Mac supports accounts managed by Microsoft Exchange Server 2007 Service Pack 1 with Update Rollup 4 (KB952580) and later versions. Make sure that your computer is connected to the network. Ask your Microsoft Exchange account administrator to tell you which proxy server to use to connect to the Microsoft Exchange server. Apr 15, 2016 Rebuild the Outlook for Mac 2011 database to resolve problems. Outlook for Mac 2011 crashes or hangs at startup. If you have additional questions or your version of Outlook for Mac is different, you may want to reach out directly to Microsoft by selecting 'Contact Answer Desk' at the top of the pages linked above.

Outlook Won't Open Processing

When Office 365 users try to open or view attachments in email messages in Outlook Web App, they experience the following symptoms:

  • In Office 365, the attachment isn't displayed in the message. Instead, a generic placeholder, such as “1 Attachment” is displayed, and this can't be opened.
  • When users try to view attachments in Office 365, they receive the following error message: Access to attachments has been blocked. Blocked attachments: .


This issue occurs if the attachment is blocked by Outlook Web App. By default, Outlook Web App blocks attachments that have the following file name extensions:

.vsmacros, .msh2xml, .msh1xml, .ps2xml, .ps1xml, .mshxml, .gadget, .mhtml, .psc2, .psc1, .msh2,.msh1, .aspx, .xml, .wsh, .wsf, .wsc, .vsw, .vst, .vss, .vbs, .vbe, .url, .tmp, .shs, .shb, .sct,.scr, .scf, .reg, .pst, .ps2, .ps1, .prg, .prf, .plg, .pif, .pcd, .ops, .mst, .msp, .msi, .msh,.msc, .mht, .mdz, .mdw, .mdt, .mde, .mdb, .mda, .maw, .mav, .mau, .mat, .mas, .mar, .maq, .mam,.mag, .maf, .mad, .lnk, .ksh, .jse, .its, .isp, .ins, .inf, .htc, .hta, .hlp, .fxp, .exe, .der,.csh, .crt, .cpl, .com, .cmd, .chm, .cer, .bat, .bas, .asx, .asp, .app, .adp, .ade, .ws, .vb, .js


Change the Outlook Web App mailbox policy to include and exclude the file types that you want.

The following is an example of the Windows PowerShell commands to remove the .xml file type from the BlockedFileTypes and BlockedMimeTypes lists and add it to the AllowedFileTypes and AllowedMimeTypes lists:

Things to consider:

  • It may take several minutes before changes to the Outlook Web App policy take effect.
  • Be aware that by changing the Outlook Web App mailbox policy to include file types that are blocked by default, you may make your system more vulnerable to security threats.


Direct users to compress the files that they intend to send (for example, as a .zip file) and then send the compressed files as attachments.

More information

Still need help? Go to Microsoft Community.

I have Outlook 2016 installed on a Windows 10 64-bit system and up till now it’s been working fine. Yesterday, I went to open it and I got the following error message:

What’s sad is that I’ve had this EXACT same problem in Outlook 2010 and I even wrote about an article about it over a year ago:

For whatever reason, the solution to the problem in Outlook 2010 is different and none of those methods worked for me when trying to fix it for 2016. So read the previous post and if nothing there works for you, then try the methods listed below.

Method 1 – Delete Registry Key

Microsoft Outlook 2010 Won't Open

Click on Start and type in regedit to open the registry editor in Windows.

And then tried something else – SharePoint Designer 2013 to connect to Project Online for creating workflows. Like Project, SharePoint Designer doesn’t have a Mac version – so this could be another scenario where the virtual environment on the Mac is useful for the SharePoint and Project Online user who prefers to keep with their Mac. Microsoft project online for mac. Just follow these instructions to install Microsoft Project on Mac. Make sure you have plenty of hard drive space. We’d recommend at least 30GB to give Parallels, Windows, Office and Project plenty of space to install on your Mac. Basically, the more space you have on your hard drive.

Navigate to the following key in the registry:

Now delete the Profiles key that is under Windows Messaging Subsystem. Restart your computer and try to open Outlook 2010. Hopefully that fixes your problem!

Microsoft error reporting problem with mac

Method 2 – Install Latest Service Pack and Microsoft Upates

The next thing you can try if that didn’t work for you is to install the latest Office updates. You can do this by opening any Office program, then clicking on FileAccount. On the right-hand side, you’ll see production information. Under that, there is a section called Office Updates. Click on the Update Options button and choose Update Now.

This has fixed the problem for quite a few people, so if nothing else is working for you, then definitely install latest Office updates and Windows updates.

Method 3 – Open Task Manger/Kill Process

This problem of Outlook not starting can also be caused by multiple instances of Outlook running without being properly killed. If you go into Task Manger (Ctrl + Shift + Esc), you should only see one Outlook process running.

Microsoft Outlook Mac Desktop Won't Open Windows 10

If you see more than one outlook.exe in the process list, go ahead and select each one and choose End Process. Once you have killed off all of the Outlook processes, then try to restart Outlook and see if it loads properly.

Microsoft Outlook Mac Desktop Won't Open Windows 7

So there you have a couple of more possible solutions to this very annoying problem! If you have found a different solution, post a comment here and let us know! Enjoy!