All versions of Outlook since Outlook 2000 Service Release 1 include a security feature that blocks attachments that could put your computer at risk from viruses or other threats. For example, certain types of files (such as .exe files) that are sent as attachments are automatically blocked. Although Outlook blocks access to the attachment, the attachment remains in the e-mail message.
Enable Blocked Attachments in Microsoft Outlook
If Outlook blocks an attachment, you won't be able to save, delete, open, print, or work with the attachment in Outlook. However, here are four methods designed for novice and intermediate computer users to work around this problem.
Ask the sender to save the attachment to a cloud storage service, server, or FTP site and send you a link to the attachment. Click the link to open the attachment and save it to your computer.
If there is no server or FTP site available to you, ask the sender to use a file compression utility to compress the file. This step creates a compressed archive file with a different file name extension. Outlook does not recognize these file name extensions as potential threats and does not block the attachment.
