Cyber security softwares like Trend Micro features a built in Virtual Analyzer and Time-of-Click Protection, where outgoing and incoming emails are scanned for malicious URL's before they are delivered to their destination.
To avoid HotDocs URLs sent by View Legal from being blocked or filtered, add URLs in your company’s security system approved list.
Here is a helpful resource how to add URL in the approved URL list - https://success.trendmicro.com/solution/1054744-adding-a-url-in-the-approved-url-list-in-worry-free-business-security-wfbs