Function works when Safari is the default browser, does not work when Firefox or Chrome are choosen as the default browser.
iMac 24″, macOS 14.0
I have the same problem in macOS Sonoma Mail, except Safari is my default browser. I think this started with the release of Sonoma, but I'm not sure of that.
I'm glad to see I'm not the only one and that other's have similar problems.
BTW this still happens with a fresh install of Sonoma in a newly erased and formatted SSD.
When I try to use the "open link behind mail" (right click option) on links in mail they open but NOT behind email? It works fine in Safari.
