If you are sending review links to a client in a company that uses a strict firewall we have a couple of recommendations you can give your client to help Wipster links and notification emails get past it.
These are:
1. Add no-reply@wipster.io to safe senders list for email
2. Allow http and https traffic to:
wipster.io
app.wipster.io
cdn.wipster.io
m.wipster.io
beta.wipster.io