I started having problems looking at my Gmail and my Google Apps for your domain mail in firefox recently,Google kept saying “We’re sorry. It seems there is a problem. Please try using Gmail with a supported browser.”

fter a bit of research I have determined that it is due to to the User-Agent header in firefox having changed and Google not having updated their code to take account of this. I have two solutions that you can use.

  1. disable the browser checking by appending ?nobrowsercheck to the url, so for gmail type in
    http://mail.google.com/mail/?nocheckbrowser
    and for google apps for your domain type in
    http://mail.google.com/a/yourdomain.com/?nocheckbrowser
    obviously replacing the domain with your own.
  2. edit the browser agent string in firefox to something older, so in the address box type in
    about:config
    and then scroll down to general.useragent.extra.firefox
    and double click on it and change it to Mozilla Gecko Firefox/1.5.0.4

I prefer the first solution, but either work.