Litmus sends out email that breaks
The attached link was from Litmus mail out to all clients, to promote their new toolsets that relate to the Apple Watch.
Unfortunately, and rather embarrassingly, for the email testing company, is that the links were broken. The analytics for the Apple Watch link in the email seem to break when users clicked on them. The result was users being brought to a page that simply says..."Error establishing a database connection". For the more dev-head user, simply removing the "utm_campaign" related querystrings gets you to were you wanted to go.
https://litmus.com/blog/apple-watch-favors-text-version-breaks-links?utm_campaign=apr2015news&utm_source=Pardot&utm_medium=email