When you open a specific attachment in Outlook you might get the error saying Outlook blocked access to the following potentially unsafe attachments. Here’s a some solutions to help you unblock attachments in Outlook
Make sure that Outlook is closed. Open Registry and go to the below area depending on your office application version
Microsoft Office Outlook 2010
Microsoft Office Outlook 2007
Microsoft Office Outlook 2003
Microsoft Outlook 2002
Microsoft Outlook 2000
Create a new String Value and enter
As the value enter the extension of the file example
.pptx, if you want to add multiple extensions, seperate them with a semicolon like this,
Close regedit and open Outlook
If this doesn’t work then you might have an update that blocks as Microsoft have released a patch which blocks safe files.
If you do have the below updates according to the Office version, remove them.
Outlook 2007: KB3191898
Outlook 2010: KB3203467
Outlook 2013: KB3191938
Outlook 2016: KB3191932
When having a local setup of Exchange and you want to migrate to Office 365 while leaving the local Exchange in place, you will have problems with autodiscover still pointing users to the local Exchange setup. If you don’t do the below, Outlook will still try to connect to the old Exchange server.
To stop the Autodiscover, open ADSIEDIT.MSC from the Active Directory server and delete the below entry so that the local SCP entry is skipped.
Select the “Configuration” naming context
CN=Exchange Administrative Groups\
And delete the CN= of class serviceConnectionPoint
Since Outlook uses SCP as well, you might want to run this registry update on the local machines.
(The version number varies depending on your Office application version)
– Navigate to HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\AutoDiscover
– Create new DWord ExcludeScpLookup
– Set the DWord as 1
After this, try to ping autodiscover.mydomain.com to ensure that it’s pointing to the Office 365
You can also do the following maybe it will help more. These should be created under the AutoDiscover Key
When setting up the automatic reply and out of office from your Outlook 2010 having Exchange 2010 you might have the problem with a pop-up saying “Your automatic reply settings cannot be displayed because the server is unavailable”.
I have managed to solve this with a DNS record in your infrastructure. Create the following SRV record to fix the issue.
Port Number: 443
On the client PC run the following to refresh the DNS. Make sure you run the CMD as Administrator
This should fix the problem and the user will be prompted to enter his Out of office settings.
When opening Outlook 2003, you might have the error “MAPI32.DLL is corrupt or the wrong version“. This can be if you had a newer version of Microsoft Office, un-installed it and installed Microsoft Office 2003. This can be fixed by renaming the MAPI file on your computer as above:
:\Program Files\Common Files\System\Msmapi\1033