Blocked Outlook File Attachments

Microsoft has just banned additional file types including Java, Python, and PowerShell extensions

One of the most common ways of transmitting computer viruses is through file attachments. To help protect you and your recipients against computer viruses, Outlook blocks the sending and receiving of certain types of files (such as .exe and certain database files) as attachments. If you need to send one of these file types to an email recipient, we recommend using OneDrive and sending the recipient a link to the file instead.

Note: If you're using a Microsoft Exchange account, your email server administrator can unblock certain file types. Contact your administrator for more assistance.

The List. New file types are highlighted in Yellow:

Extension File type Extension File type
.ade Access Project Extension (Microsoft) .msh2 Microsoft Shell
.adp Access Project (Microsoft) .msh2xml Microsoft Shell
.app Executable Application .mshxml Microsoft Shell
.appcontent-ms Third Party Software Exploits .msi Windows Installer File (Microsoft)
.asp Active Server Page .msp Windows Installer Update
.bas BASIC Source Code .mst Windows SDK Setup Transform Script
.bat Batch Processing .msu Windows Update file
.cer Internet Security Certificate File .ops Office Profile Settings File
.chm Compiled HTML Help .osd Open Software Description 
.cmd DOS CP/M Command File, Command File for Windows NT .pcd Visual Test (Microsoft)
.cnt Microsoft Help Workshop Application .pif Windows Program Information File (Microsoft)
.com Command .pl Perl script
.cpl Windows Control Panel Extension (Microsoft) .plg Developer Studio Build Log
.crt Certificate File .prf Windows System File
.csh csh Script .prg Program File
.der DER Encoded X509 Certificate File .printerexport Printer backup file
.diagcab Microsoft Support diagnostic tools .ps1 Windows PowerShell
.exe Executable File .ps1xml Windows PowerShell
.fxp FoxPro Compiled Source (Microsoft) .ps2 Windows PowerShell
.gadget Windows Vista gadget .ps2xml Windows PowerShell
.grp Microsoft program group .psc1 Windows PowerShell
.hlp Windows Help File .psc2 Windows PowerShell
.hpj AppWizard Help project .psd1 Windows PowerShell
.hta Hypertext Application .psdm1 Windows PowerShell
.inf Information or Setup File .psl Power Shell Files
.ins IIS Internet Communications Settings (Microsoft) .pst MS Exchange Address Book File, Outlook Personal Folder File (Microsoft)
.isp IIS Internet Service Provider Settings (Microsoft) .pyc Python Files
.its Internet Document Set, Internet Translation .pyo Python Files
.jar Java Archive .pyw Python Files
.jnlp Java Network Launch Protocol .pyz Python Files
.js JavaScript Source Code .pyzx Python Files
.jse JScript Encoded Script File .reg Registration Information/Key for W95/98, Registry Data File
.ksh UNIX Shell Script .scf Windows Explorer Command
.lnk Windows Shortcut File .scr Windows Screen Saver
.mad Access Module Shortcut (Microsoft) .sct Windows Script Component, Foxpro Screen (Microsoft)
.maf Access (Microsoft) .settingcontent-ms Third Party Software Exploits
.mag Access Diagram Shortcut (Microsoft) .shb Windows Shortcut into a Document
.mam Access Macro Shortcut (Microsoft) .shs Shell Scrap Object File
.maq Access Query Shortcut (Microsoft) .theme Desktop theme file settings
.mar Access Report Shortcut (Microsoft) .tmp Temporary File/Folder
.mas Access Stored Procedures (Microsoft) .url Internet Location
.mat Access Table Shortcut (Microsoft) .vb VBScript File or Any Visual Basic Source
.mau Media Attachment Unit .vbe VBScript Encoded Script File
.mav Access View Shortcut (Microsoft) .vbp Visual Basic project file
.maw Access Data Access Page (Microsoft) .vbs VBScript Script File, Visual Basic for Applications Script
.mcf Media Container Format .vsmacros Visual Studio .NET Binary-based Macro Project (Microsoft)
.mda Access Add-in (Microsoft), MDA Access 2 Workgroup (Microsoft) .vsw Visio Workspace File (Microsoft)
.mdb Access Application (Microsoft), MDB Access Database (Microsoft) .webpnp Internet printing file
.mde Access MDE Database File (Microsoft) .website Pinned site shortcut from Internet Explorer
.mdt Access Add-in Data (Microsoft) .ws Windows Script File
.mdw Access Workgroup Information (Microsoft) .wsc Windows Script Component
.mdz Access Wizard Template (Microsoft) .wsf Windows Script File
.msc Microsoft Management Console Snap-in Control File (Microsoft) .wsh Windows Script Host Settings File
.msh Microsoft Shell .xbap Browser applications
.msh1 Microsoft Shell .xll Excel add-in
.msh1xml Microsoft Shell .xnk Exchange Public Folder Shortcut