It will only work if you "Always" "Accept third-party cookies and site data". Choosing "From visited" will block gmail but still allow Hotmail and Yahoo Mail.
No help on the website for this, I figured it out by trial and error. Spent months without X-notifier thus 3 stars.

Très bonne appli mais ne fonctionne plus sur Outlook depuis aujourd'hui

Meilleure appli pour mail.

excellent
thumbs up

I have used X-notifier for more than ten years. It used to be good and was a pleasure to use, but recently it has become unreliable and slow. Very poor response to bug reports.

Doesnt work.

Ottima, fa egregiamente il lavoro che deve fare.
Perfettibile l'interfaccia grafica, i nomi provider andrebbero attualizzati

It doesn't work, it worked well for the first couple of years then stopped notifying me of new emails.
If I click on my email provider in the drop down window it takes me to my email account but it doesn't notify me of new emails which is the whole point of this add on !

gmail can login ver4.2.1

As I have only just added the two extensions to Firefox, I am unable to comment, but my overall experience if Firefox is very positive, fast accurate and good graphics make Firefox my preferred user.

In the Japanese version of Yahoo! Mail(yahoo.co.jp), only the top account is valid, so even if I try to log in to another account, it will become that account. And even if I specify the default account in settings, its symptoms will not change.

And when that symptom appears, character authentication is required each time, so it becomes very difficult to use.

The security of knowing my mail won't be compromised.

crashes constantly, not worth the time to continually re-imput the information

Good time to all.
The script stopped working from Yandex.ru

I understand that yandex changed the URL
https://mail.yandex.ru/neo2 2015г.
https://mail.yandex.ru/u2709/ 2017г.

And these changes (leading to a step increase) are likely to be of little importance.
this.getHtml(this.dataURL,"_handlers=folders"); в 2015г.
this.getHtml(this.dataURL,"_model.0=folders"); в 2017г.


Professionals, very much ask you to fix the script for Yandex.

Esta extensión desde hace ya varios años me da problemas con los mails de Outlook y Yahoo. No sé qué será, pero desde hace unas cuantas versiones de Firefox no me actualiza correctamente los correos de estos proveedores. De Gmail siempre va bien. Es una lástima porque es muy buena y permite estar al tanto de múltiples cuentas de correo a diario sin mucho esfuerzo.
Por favor, si alguien sabe por qué ocurre y si con algún cambio en el código se puede solucionar, lo agradecería.