gakabane said

that are written by other people

Are you talking about ads? Neither Firefox nor your e-mail provider can do much for this problem.

However,

Some e-mail providers have the option to sort incoming mail. Contact your e-mail provider for help.

Go here and register for protection for your e-mail and phones; https://www.donotcall.gov/ The National Do Not Call Registry

gakabane said

I keep receiving e-mails from my own e-mail address that are written by other people and sent to me (and maybe to other people too??) I cannot move them to junk as it is my own e-mail address. Any suggestions?

First thing to do : change your password  !

Hi gakabane, some webmail sites allow you to create rules for filing away messages automatically, separate from junk mail filters. That could help. Details would depend on the mail site. Do you want to mention which one it is?

Thank you. I use hotmail, so I have been getting mail from my xxxxx @hotmail.com email, which is my own e-mail address.

I have tried changing my password. That did not solve the problem.

Never post any personal information because an adware robot could find it, and start sending you all kinds of spam. This includes e-mail, phone, and home information.

Please remove that information from your post.

Many ad senders use code to make the e-mail seem to come from whoever they are sending it to.

What I did was to set my options to send anything from me to the junk folder.