What changed exactly -- was it your webmail site made a layout change or you updated Firefox or installed a new add-on or you have a different home page?

If the problem is on your webmail site, here's some general advice:

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) Bypass Firefox's Cache

Use Ctrl+Shift+r to reload the page fresh from the server.

Alternately, you also can clear Firefox's cache completely using:

orange Firefox button (or Tools menu) > Options > Advanced

On the Network mini-tab > Cached Web Content : "Clear Now"

If you have a large hard drive, this might take a few minutes.

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

• right-click and choose View Page Info > Security > "View Cookies"
• Alt+t (open the classic Tools menu) > Page Info > Security > "View Cookies"

In the dialog that appears, you can remove the site's cookies individually.

Then try reloading the page. Does that help?

There were folders that were available to store emails in on the left side of the email listing. They are no longer there. Where did they go and how can I get them back?

Which web based email service are you using?

Start Firefox in Safe Mode to check if one of the extensions (Firefox/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem (switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance).

• Do NOT click the Reset button on the Safe Mode start window or otherwise make changes.

• https://support.mozilla.org/kb/Safe+Mode
• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

Which email site are you using? If it's a popular one (e.g., Yahoo, Hotmail, Outlook.com, Gmail) a volunteer could take a look and see how to change the layout. If it's obscure, you might need support from the site.

Problem solved.

Problem solved.