I’ve received a couple e-mails concerning the link in the Get Mail Extension entry not working. After a little research I found out the extension was no longer on the main AMO (addons.mozilla.org) section or even in the sandbox. Further research via Google I found out the author’s site for Get Mail (he also did ChromEdit Plus) extensions. From the Get Mail FAQs:
When AMO recently updated their site… It was MY personal decision to remove ALL of my extensions from AMO at this point in time.