There was a change in Firefox 54 that cause the Send button in Earthlink webmail not to work at all. Either it was grayed out or when you clicked it, nothing happened. Earthlink fixed it on their end, so if you still have that problem, please try "the usual":

Cache and Cookies: When you have a problem with one particular site, a good "first thing to try" is clearing your Firefox cache and deleting your saved cookies for the site.

(1) Clear Firefox's Cache

See: How to clear the Firefox cache

If you have a large hard drive, this might take a few minutes. If you do not see the number going down on the page, you can reload it using Ctrl+r to check progress.

(2) Remove the site's cookies (save any pending work first). While viewing a page on the site, try either:

• right-click (on Mac Ctrl+click) a blank area of the page and choose View Page Info > Security > "View Cookies"
• (menu bar) Tools > Page Info > Security > "View Cookies"
• click the padlock or "i" icon in the address bar, then the ">" button, then More Information, and finally the "View Cookies" button

In the dialog that opens, the current site should be pre-filled in the search box at the top of the dialog so you can remove that site's cookies individually.

Then try reloading the page. Does that help?

If the site shows that you are sending the message, and it appears in your Sent or Sent Items folder (whatever they call it), I'm not sure how it could be a Firefox problem. What if you create a test message and address it to yourself and send it. Can you receive that one?

had that problem as well last week...but is fixed...i don't have the grey button; in fact earthlink says msg successfully sent and it shows up in my sent folder...but it's not really received...oddly, if i forward the msg in the sent folder, it works...same problem w/chrome but not explorer

had that problem as well last week...but is fixed...i don't have the grey button; in fact earthlink says msg successfully sent and it shows up in my sent folder...but it's not really received...oddly, if i forward the msg in the sent folder, it works...same problem w/chrome but not explorer

That's bizarre. What secret sauce is IE adding that Firefox and Chrome aren't? Perhaps some spam filter on the other end finds the HTML tags in IE messages to be preferable in some respect?

Speaking of HTML tags... I was testing an extension called Page Zoom WE and it inserted all sorts of extra font size information into anything I composed. You may want to "view source" on your Firefox and IE messages (of course, it's easiest if the messages are identical) to see whether you notice any differences that could be caused by add-ons.