How can I eliminate SPAM !!

Is this spam email? If it is, Firefox has no email options. If you are accessing email through Firefox it will be a webmail service. If that is the case you can check with the support for the webmail service to see if they offer a spam filter.

If it is pop-ups, see http://kb.mozillazine.org/Popups_not_blocked

Using your email address as your user name won't do you good either.

You should never post your email address on public forums.
Such forums are visited by spam bots that harvest email addresses and if they catch yours then you may receive a lot of spam.