Ditto.
I tried, Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:128.0) Gecko/20100101 Firefox/128.0 SeaMonkey/2.53.23, & still nonsense from
www.mail.com.
Then, in SeaMonkey, (where
www.mail.com does load, normally) I changed SM's UA to, Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:128.0) Gecko/20100101 Goanna/6.8 Firefox/128.0 PaleMoon/33.9.0, &
www.mail.com still loaded as expected.
(As it was, yesterday, mail.yahoo.com forced a new "agreement" on me, & after that my no-javascript version was "upgraded" to their upgrade version, which is utter trash, *and*, still did not work, fully, *and* ran like utter crap, literally taking minutes to open a mail message - if it opened at all.
At some point in the day, many hours later, all returned back to normal, & my no-javascript version was back working as expected.)