I have a custom Profile Centre and I'm using CloudPagesURL() to pass subscriber info and redirect to the centre. Some of the corporate subscribers who are using "Mimecast" are complaining about a warning when clicking an email => "This link downloads a file".

What could be the problem?

I have a custom Profile Centre and I'm using CloudPagesURL() to pass subscriber info and redirect to the centre. Some of the corporate subscribers who are using "Mimecast" are complaining about a warning when clicking an unsubscribe link within the email => "This link downloads a file".

What could be the problem on the Marketing Cloud side of things?