Outlook 2016 is sending corrupt attachments that cannot be opened on the receiving end.
The original file was confirmed to be fine and could be opened on the sending computer. Once it was attached to an email and sent however, it could no longer be opened.
The error when trying to open the file is:
We’re sorry. We can’t open because we found a problem with its contents.
MS Word further responds saying the file is corrupt and cannot be fixed.
It turns out this is a problem with the Adobe Send and Track Add-in for Outlook.
- Go to File, Options, Add-ins
- At the bottom click Go, beside COM Add-ins
- Unclick the checkmark beside Adobe Send and Track Add-in for Outlook
- Click Ok, then restart Outlook
Adobe Send and Track allows you to send large files as an attachment using Adobe Document Cloud. Obviously if you un-click this Add-in you no longer have that feature.
Adobe is somehow changing the file so that you receive a corrupt attachment on the receiving end.
NOTE: The Adobe support page says that this Add-in will not work if your Outlook message format is RTF (Rich Text), so that might also be something to check. Most emails these days are sent in HTML format. You can check your message format in Outlook 2016 by going to File -> Options -> Mail.