Clicky

Microsoft Technical Bulletins

The latest updates for all the Microsoft Products you use every day.

Written by Brad

Categories: Microsoft 365 Apps

July 27, 2022

Blog Home

Outlook to block new attachment file types to improve security

Microsoft 365 Apps, Microsoft 365 Experts

From Microsoft Corporation
Technical Bulletin MC395211 · Published Jun 27, 2022

Message Summary

As we continually assess to improve security, we are adding additional attachment file types to the list of BlockedFileTypes.

When this will happen:

We will begin rolling out early July and expect to complete by late July.

How this will affect your organization:

The newly blocked file types are rarely used, so most organizations will not be affected by the change. However, if your users are sending and receiving affected attachments, they will report that they are no longer able to download them.

What you need to do to prepare:

There are several ways to send and receive a blocked file. You can save the file to the cloud and send a link to the file, use a file compression utility like WinZip, or even rename the file with another extension, then have your recipient change the name back to the original name after they receive the file.

What file extensions will be added to the BlockedFileTypes list with this change?

Outlook Win32: “.cab”,

Outlook on Web: “application”, “bgi”, “img”, “.iso”, “cab”

New Outlook on Mac, Outlook Android, Outlook iOS: “.appref-ms”, “.cdxml”, “.mht”, .mhtml”, “.pssc”, “.udl”, “.wsb” “.cab”

Where is the fu​ll list of Outlook client block file types?

Outlook Win32: Blocked attachments in Outlook (microsoft.com)

Outlook on Web: Changes to File Types Blocked in Outlook on the web – Microsoft Tech Community

New Outlook on Mac, Outlook Android, Outlook iOS

TECHNICAL BULLETIN END

QuixTec provides this and other technical bulletins unaltered from Microsoft. As an authorized Microsoft Partner, we ensure that all our solutions we deliver to you include the latest Microsoft updates.

ABOUT US: QuixTec, LLC is a U.S. certified Veteran Owned, modern DevOps organization with experience in a plethora of IT Software Languages.  As a Microsoft Partner, we specialize in Discounted Microsoft Software Licensing, Microsoft SharePoint, Microsoft365 and HTML5 technologies for small to enterprise-sized organizations. Our dedication to IT excellence is evidenced through our PECB ISO Certification training center. The only PECB ISO authorized center in Washington State. QuixTec, implements and provides training for upcoming open-source digital marketing services that are taking the industry by storm. This solution, used by over 100,000 businesses, provides enterprise level marketing capabilities at startup rates. The founder, Richard, has 30 years of experience working with several notable companies that include World Vision, Expedia, Microsoft, Levi Strauss, NASA, Boeing Aerospace, Los Alamos National Laboratory, and the U.S. Air Force, to name a few.  QuixTec is in the Seattle area. Phone today for a free consultation and project estimate.

(425) 367-9025

LEARN MORE

SharePoint Development ServicesSharePoint DevelopmentCustom Software DevelopmentMicrosoft 365 ExpertsMicrosoft 365IT Staffing ServicesIT StaffingWordPress Development ServicesForm Email ValidationMicrosoft LicensingMautic Open Source MarketingBest IT Staffing AgenciesIT Staffing Company

You May Also Like…

Outlook Mac now supports retention Policy

Outlook Mac now supports retention Policy

Exchange Online, Microsoft 365 Apps, Microsoft 365 Experts From Microsoft CorporationTechnical Bulletin MC397458 · Published Jul 5, 2022 Message Summary Use retention policies in Outlook for Mac to apply a policy to your messages in your...