Office 365 - Unable to view/open attachment

A security feature exists within many of the Office 365 clients that blocks attachments that might put your computer at risk for viruses or other threats.

What will I see in my client when I receive a message with a blocked attachment?

Outlook on the web

executable attachment

The example above shows an attachment titled "bucky_badger.exe". If you attempt to click on the image to open/view it, you will see the following message:

access blocked

Outlook for Windows

outlook access blocked

Outlook displays the above message for any attachment that has been blocked. The attachment in this example is titled "bucky_badger.exe".

Note: All executable files should be handled with great caution. Please contact the sender to verify that they intended to send it to you and that it is safe to execute. Keep in mind that some viruses are constructed in a way to trick you into trusting that the file is safe to open.

How can I get the attachment if I cannot see it or open it?

My desktop anti-virus program doesn't detect a virus in the message, is it ok to open the attachment?

You should not execute any unverified file attachments even if your anti-virus program doesn't detect a threat. It is common for every anti-virus program to miss some new viruses.

What file types are considered executable?

*.ade *.adp *.app
*.asp *.aspx *.asx
*.bas *.bat *.cer
*.chm *.cmd *.com
*.cpl *.crt *.csh
*.der *.exe *.fxp
*.hlp *.hta *.htc
*.inf *.ins *.isp
*.its *.js *.jse
*.ksh *.lnk *.mad
*.maf *.mag *.mam
*.maq *.mar *.mas
*.mat *.mau *.mav
*.maw *.mda *.mdb
*.mde *.mdt *.mdw
*.mdz *.mht *.mhtml
*.msc *.msh *.msh1
*.msh2 *.msi *.msp
*.mst *.ops *.pcd
*.pif *.plg *.prf
*.prg *.psl *.ps2
*.psc1 *.psc2 *.pst
*.reg *.scf *.scr
*.sct *.shb *.shs
*.tmp *.url *.vb
*.vbe *.vbs *.vss
*.vst *.vsw *.ws
*.wsc *.wsf *.wsh

Other resources/information: