If I click on the link in the E-Mail I get a warning message:
Pasting the link into the browser causes a 'Page Not Found' error.The link you just clicked seems to lead to another site than what the link text indicated. This is sometimes used for tracking whether you clicked the link, but it could also be a scam.
The link text indicated that the link would lead to www.nowtv.com, but it leads to communicatoremail.com.
I therefore logged onto my account and found the page where you redeem passes. I entered the voucher code and got the following message:
How I Sorted it through a web browser."Hmmm, we don't recognise that voucher code. Check you entered it correctly and try again".
Go into your NOWTV account. (you might have to create an account if you don't have one) https://www.nowtv.com/ie/sign-in
Start to Purchase a Sky Sports Pass as normal. https://www.nowtv.com/home/existing
Choose the day pass
Follow all the rigermerol through until you come to the payment screen.
There should be a box on the payment screen that enables you to enter the voucher code.
This worked.
P.S. Nowtv didn't like Firefox.