Microsoft Office 365 may warn your email recipient with a warning as shown below if it finds what it considers to be "Link Masking" within your email campaign:
A Link Mask is where the email indicates a hyperlink with a destination of a particular website address whereas in fact the recipient will be taken to a different website address when they click. Phishing attacks regularly use this method to deceive, so you can understand why Microsoft is displaying a warning.
When Enudge tracks clicks on the hyperlinks inside your email, it first takes the reader to an Enudge website address (to record the click) and then re-directs the reader to the real destination website address. This is done without the recipient seeing anything except, if they are paying close attention, they will notice the URL change in the address bar. NB: the re-direct does not trigger the link mask warning, what does trigger the issue is including text in the hyperlink that purports to be a different website address compared to where the link will actually take the reader.
How to avoid the warning?
The simple solution, as shown in the image below, is to always use words to hyperlink to a web address, and NOT a web address.