User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:49.0) Gecko/20100101 Firefox/49.0 SeaMonkey/2.46 Build ID: 20161213183751 Steps to reproduce: 1. Have an EarthLink email account. 2. Log in to http://webmail.earthlink.net. 3. Start writing a simple e-mail. 4. Either send or save a draft of it. Actual results: Nothing happens. Webmail's "Send", "Save Draft", and "Cancel" buttons become gr(a/e)yed out. Expected results: The pressed button should work for Send and "Save Draft". Cancel works fine though.
I tried multiple accounts' addresses from two MacBook Pros (El Capitan v10.11.6 and Sierra v10.12.5) and a 64-bit W7 HPE SP1 machine. No problems in other updated web browsers (Chrome, Safari, and IE11) on the same machines. I downgraded back to Firefox v53.0.3 and retested. No problems!
The issue is being tracked in Bug 1373327.