See http://lifehacker.com/392287/set-firefox-3-to-launch-gmail-for-mailto-links

Set the pref gecko.handlerService.allowRegisterFromDifferentHost to true on the about:config page.

Run this javascript code via copy and paste to the location bar and press the Enter key to run the code. navigator.registerProtocolHandler('mailto','https://mail.google.com/mail/?extsrc=mailto&url=%s','Gmail'); Do not forget to reset the pref gecko.handlerService.allowRegisterFromDifferentHost to false after you have added Gmail.

To open the about:config page, type about:config in the location (address) bar and press the Enter key, just like you type the url of a website to open a website. If you see a warning then you can confirm that you want to access that page.

thank you SO much! very much appreciate your help.

You're welcome I seem to have misread the first post and gave an answer about mailto that of course doesn't apply to RSS feeds.

Check the Web Feed settings: Tools > Options > Applications > Web Feed (Use Google or Preview in Firefox)

You can also check the pref browser.feeds.handler (reader or ask) on the about:config page.

To open the about:config page, type about:config in the location (address) bar and press the Enter key, just like you type the url of a website to open a website. If you see a warning then you can confirm that you want to access that page.

Google is no longer listed as an option in that Applications area. Is there any way to get it back?