Support?

Hi I can not work out where you can get some help in this group, so I have posted in the hope it finds the right place!

I am presently building a site in Spanish, but the back end is in English and Spanish, all is going well so far and I am impressed with the internationalization, even though I am new to Drupal and do not understand to much but learning with trial and error.

The question is I cannot find the module which enabled the translation of the emails in the Accounts settings section or even change the choice of the posting language for Articles and pages etc. I did have it working once but for the life of me I cannot remember, which module I used.

Any help here would be appreciated

Regards
Stephen