how to clean a wrong email format

Please help me to clean an email from junks. I have to delete the junks after "@" and before "@". What functions to build to clean the junks in one go to bring the corect email? Here is the junks that i have to delete before "@" and after "@":


@.site.com, biz, info etc
@..(dot or dots)
@1234 etc
@ “space”
@www
@.....site…com
@duplicate

admin, contact, info, support, webmaster , cv, sales, help, office, server, test, host, games, game, press, news