Mutt and Postfix problem

*Sorry if this question is in the wrong sub-reddit

I have been trying to learn Postfix with Mutt as my MUA. I had set up users, Mutt had given them mail boxes, everything was working great :)

I then attempted virtual domains: virtual_alias_domains = ................ virtual_alais_maps = ................. In my main.cf file

I then created a file showing: alias@blah.org user

and then used postmap /file postfix reload

This was a complete failure, with the added blow of none of my "normal" users being able to send mail.

I re-installed postfix and mutt but nothing is working.

Can any admins offer advice on this situation or direct me to my mistake?

Thanks for reading :)