Some email service providers have moved to newer email protocols for improved security and reliability. These email service providers may no longer work with Windows Live Mail.
To help protect your computer from viruses—programs that can harm your computer or access your private information—Windows Live Mail blocks some types of attachments that have a higher risk of containing a virus. If Mail blocks an attachment that you receive, the warning Prohibited file type is displayed in the message header, and the attachment can't be downloaded or opened.
To always allow all types of attachments, you can change this setting in Safety options. After changing this setting, you will be able to download and open all types of attachments; however, changing this setting won't unblock attachments that Mail has already received. To allow these types of attachments for certain messages, you can ask the sender to compress (or zip) an attachment before sending it.
Turning this off may leave your computer at risk from viruses and isn't recommended.
Article ID: 10740 - Last Review: 31 Aug 2016 - Revision: 16