Activate link in Activate email doesn't work on old Mac using Firefox

[katska]

On receiving an activate your account email, someone who uses Planning Alerts reports that:

"When I put the cursor on what is meant to be the link, it is a short vertical line and doesn’t change to a hand. Using Firefox on a 10 year old MacBook

@mlandauer What technology are we aiming to support? Can we offer an alernative route for when something like this crops up?