Given the level of post to this forum, groupon have changed something. But As I have never seen one of their mail I do not have any idea what.

Perhaps you could forward one to me (as an attachment so click the down arrow beside the forward button) at matt_AU at gmx dot com

The Groupon email messages appear to contain invalid URLs (at least as far as Thunderbird is concerned).

The URLs have linefeed characters prior to the 'http'.

For example, looking at one of the message in 'source' mode, I see most URLs as:

< http://etc..etc.etc..>

And TB is throwing an invalid URL error (see them in the Error Console). But I think TB is correct, and Groupon is sending bad URLs....

FWIW: A few URLs in the messages are as: <http://etc,etc...> and these work....

I've tried to get through to someone at Groupon, but no luck so far.

Couple interesting things I found in troubleshooting this problem. I rebuilt my machine moving to Ubuntu 18.04(not due to this problem but was good timing) and reloaded Thunderbird. The problem still occurs so I don't think it's specific to my machine. I also found that when I hover over any of the links in the emails that do not work, rt click and select copy link address, nothing is copied. All other emails where links work, including those from Groupon and Living Social prior to 6/27 it copies a link.

Any thoughts on if there was a problem with the links being sent from groupon, why would they work directly in a browser, and 2 why would there not be lots of board chatter about the problem???

Thanks

Seems to be an issue experienced by people: https://answers.microsoft.com/en-us/edge/forum/edge_other-edge_win10/as-of-today-when-i-try-to-click-on-a-groupon-link/87f88d44-f6e6-452d-9ebb-5f6be63c2362

You mention: The URLs have linefeed characters prior to the 'http'.

Some one posted info... All the Groupon links have an extra space (%20) character at the beginning of the URL string before the 'https://...'

This sounds like groupon have made an error.

I'm having the same problem. does anyone have a solution to unblock my Groupon emails on Thunderbird

It would seem I have not made it clear enough that the additional spaces included in the groupon email mean the link is not a true link. The added extra spaces should not be there. This is a widely reported issue on many forums and has been reported as occuring in a variety of email clients and mail apps including Windows 'Mail', Outlook, Thunderbird and MAC Mail.

Please copy the actual link and not the extra spaces. The means copy from the h of http and not include the extra spaces prior to the http. Then paste into the address bar of your browser. This will get you to the correct webpage.

Suggest those effected report the issue to groupon.

I haven't received a new email today from Groupon, but the one I received from Living Social worked. .

As of today's email from Groupon, It appears both are now working.