Hi

Firefox itself does not have an email contacts list as it is a web browser. You may be looking for the contacts on the page of your email service provider. I recommend you contact them for assistance with this issue.

raykay36 said

How do I locate my Firefox Email Contact List?

In case you use Thunderbird : you can post your question on the Thunderbird support forum (just click on 'Ask a Question' at the top of the page).

https://support.mozilla.org/en-US/products/thunderbird