If you are asked to put your email address in a form, you would, of course, use your normal email address, such as xxxxxxxxx@xxx.xxx
However, if you are mentioning your email address casually in a post as in a blog, on Facebook, or elsewhere, to avoid spam and other nuisance issues, spell out the "@" and the "." - for example, you would say xxxxxxxxx at xxx dot.xxx
People who need to reach you at that address will know to replace the spelled-out words with the correct symbols (or we would hope so!).
