Microsoft bans 38 file extensions from Outlook to stop you downloading viruses

Email warning
(Image credit: Shutterstock)

Microsoft has banned 38 new file extensions from Outlook online, bringing the total number of forbidden file types to 104.

The company hasn't said exactly when the change will roll out, but it's expected to come into force very soon. When it does, you will no longer be able to download files with the blacklisted extensions unless your system admin has made a specific exception.

As ZDNet reports, the newly blocked file types are often used to send malicious content, but are rarely used legitimately, so Microsoft doesn't expect the update to cause much trouble for Outlook users.

Safety first

The new blacklist includes Java, PowerShell and Python files, plus digital certificates and files that could be used to exploit security vulnerabilities in third-party software. Many of those vulnerabilities have now been patched, but Microsoft has decided to block them anyway for the benefit of anyone running outdated software. For more details, check out Microsoft's full list of all banned file types.

If you do happen to use any of these file extensions, Microsoft has also put together a guide explaining how to whitelist any that you need.

TOPICS
Cat Ellis
Homes Editor

Cat is TechRadar's Homes Editor specializing in kitchen appliances and smart home technology. She's been a tech journalist for 15 years, and is here to help you choose the right devices for your home and do more with them. When not working she's a keen home baker, and makes a pretty mean macaron.

Latest in Software & Services
woman listening to computer
AWS vs Azure: choosing the right platform to maximize your company's investment
A person at a desktop computer working on spreadsheet tables.
Trello vs Jira: which project management solution is best for you?
Autonomous finance
Quickbooks vs Quicken: what are the main strengths and weaknesses for your business
finance
Quickbooks vs Xero: which is the best for your business?
Group of people meeting
Zoom vs Google Meet: which is the best video conferencing tool for your business?
Fingers typing on a computer keyboard.
Microsoft 365 Personal vs Microsoft 365 Family: are there any real differences?
Latest in News
Google Pixel 8a in aloe green showing
Google Pixel 9a benchmark link teases the performance of the upcoming mid-ranger
Quordle on a smartphone held in a hand
Quordle hints and answers for Monday, March 17 (game #1148)
NYT Strands homescreen on a mobile phone screen, on a light blue background
NYT Strands hints and answers for Monday, March 17 (game #379)
NYT Connections homescreen on a phone, on a purple background
NYT Connections hints and answers for Monday, March 17 (game #645)
Apple iPhone 16 Pro HANDS ON
Leaked iPhone 17 dummy units may have given us our best look yet at all four models
A super close up image of the Google Gemini app in the Play Store
It's official: Google Assistant will be retired for phones this year, with Gemini taking over