- Collaborate for free with online versions of Microsoft Word, PowerPoint, Excel, and OneNote. Save documents, spreadsheets, and presentations online, in OneDrive.
- Problem When Office 365 users try to open or view attachments in email messages in Outlook Web App, they experience the following symptoms: In Office 365, the attachment isn't displayed in the message. Instead, a generic placeholder, such as '1 Attachment' is displayed, and this can't be opened.
- Outlook crashes even though you aren't actively using it. Outlook crashes when you start it. To help troubleshoot Outlook issues in an Office 365 environment, follow these steps. Step 1: Investigate possible issues caused by add-ins. Open a Run dialog box. To do this, use one of the following procedures, as appropriate.
Office 365 Outlook Attachment Problems 2019
Jul 21, 2020 Problem. When Office 365 users try to open or view attachments in email messages in Outlook Web App, they experience the following symptoms: In Office 365, the attachment isn't displayed in the message. Instead, a generic placeholder, such as '1 Attachment.
-->Problem
When Office 365 users try to open or view attachments in email messages in Outlook Web App, they experience the following symptoms:
- In Office 365, the attachment isn't displayed in the message. Instead, a generic placeholder, such as '1 Attachment' is displayed, and this can't be opened.
- When users try to view attachments in Office 365, they receive the following error message: Access to attachments has been blocked. Blocked attachments: <FileName>.
Cause
This issue occurs if the attachment is blocked by Outlook Web App. By default, Outlook Web App blocks attachments that have the following file name extensions: Paint for mac os x el capitan.
vsmacros, msh2xml, msh1xml, ps2xml, ps1xml, mshxml, gadget, mhtml, psc2, psc1, msh2,msh1, aspx, xml, wsh, wsf, wsc, vsw, vst, vss, vbs, vbe, url, tmp, shs, shb, sct,scr, scf, reg, pst, ps2, ps1, prg, prf, plg, pif, pcd, ops, mst, msp, msi, msh,msc, mht, mdz, mdw, mdt, mde, mdb, mda, maw, mav, mau, mat, mas, mar, maq, mam,mag, maf, mad, lnk, ksh, jse, its, isp, ins, inf, htc, hta, hlp, fxp, exe, der,csh, crt, cpl, com, cmd, chm, cer, bat, bas, asx, asp, app, adp, ade, ws, vb, js
Solution
Outlook 365 Attachment Issues
Change the Outlook Web App mailbox policy to include and exclude the file types that you want.
The following is an example of the Windows PowerShell commands to remove the .xml file type from the BlockedFileTypes and BlockedMimeTypes lists and add it to the AllowedFileTypes and AllowedMimeTypes lists:
Things to consider:
- It may take several minutes before changes to the Outlook Web App policy take effect.
- Be aware that by changing the Outlook Web App mailbox policy to include file types that are blocked by default, you may make your system more vulnerable to security threats.
Workaround
Direct users to compress the files that they intend to send (for example, as a .zip file) and then send the compressed files as attachments.
More information
Still need help? Go to Microsoft Community.