The list below details the attachments that are blocked by default by Outlook 2013.
To unblock the attachments, see Outlook 2013 – How to unblock ‘potentially unsafe’ attachments
| File extension | File type |
|---|---|
| ade | Access Project Extension (Microsoft) |
| adp | Access Project (Microsoft) |
| app | Executable Application |
| asp | Active Server Page |
| bas | BASIC Source Code |
| bat | Batch Processing |
| cer | Internet Security Certificate File |
| chm | Compiled HTML Help |
| cmd | DOS CP/M Command File, Command File for Windows NT |
| com | Command |
| cpl | Windows Control Panel Extension (Microsoft) |
| crt | Certificate File |
| csh | csh Script |
| exe | Executable File |
| fxp | FoxPro Compiled Source (Microsoft) |
| gadget | Windows Vista gadget |
| hlp | Windows Help File |
| hta | Hypertext Application |
| inf | Information or Setup File |
| ins | IIS Internet Communications Settings (Microsoft) |
| isp | IIS Internet Service Provider Settings (Microsoft) |
| its | Internet Document Set, Internet Translation |
| js | JavaScript Source Code |
| jse | JScript Encoded Script File |
| ksh | UNIX Shell Script |
| lnk | Windows Shortcut File |
| mad | Access Module Shortcut (Microsoft) |
| maf | Access (Microsoft) |
| mag | Access Diagram Shortcut (Microsoft) |
| mam | Access Macro Shortcut (Microsoft) |
| maq | Access Query Shortcut (Microsoft) |
| mar | Access Report Shortcut (Microsoft) |
| mas | Access Stored Procedures (Microsoft) |
| mat | Access Table Shortcut (Microsoft) |
| mau | |
| mav | Access View Shortcut (Microsoft) |
| maw | Access Data Access Page (Microsoft) |
| mda | Access Add-in (Microsoft), MDA Access 2 Workgroup (Microsoft) |
| mdb | Access Application (Microsoft), MDB Access Database (Microsoft) |
| mde | Access MDE Database File (Microsoft) |
| mdt | Access Add-in Data (Microsoft) |
| mdw | Access Workgroup Information (Microsoft) |
| mdz | Access Wizard Template (Microsoft) |
| msc | Microsoft Management Console Snap-in Control File (Microsoft) |
| msi | Windows Installer File (Microsoft) |
| msp | Windows Installer Patch |
| mst | Windows SDK Setup Transform Script |
| ops | Office Profile Settings File |
| pcd | Visual Test (Microsoft) |
| pif | Windows Program Information File (Microsoft) |
| prf | Windows System File |
| prg | Program File |
| pst | MS Exchange Address Book File, Outlook Personal Folder File (Microsoft) |
| reg | Registration Information/Key for W95/98, Registry Data File |
| scf | Windows Explorer Command |
| scr | Windows Screen Saver |
| sct | Windows Script Component, Foxpro Screen (Microsoft) |
| shb | Windows Shortcut into a Document |
| shs | Shell Scrap Object File |
| tmp | Temporary File/Folder |
| url | Internet Location |
| vb | VBScript File or Any VisualBasic Source |
| vbe | VBScript Encoded Script File |
| vbs | VBScript Script File, Visual Basic for Applications Script |
| vsmacros | Visual Studio .NET Binary-based Macro Project (Microsoft) |
| vss | Visio Stencil (Microsoft) |
| vst | Visio Template (Microsoft) |
| vsw | Visio Workspace File (Microsoft) |
| ws | Windows Script File |
| wsc | Windows Script Component |
| wsf | Windows Script File |
| wsh | Windows Script Host Settings File |