You're still using an MUA. You can find out exactly which one by typing
The output should be something like
lrwxrwxrwx 1 root root 4 2005-02-20 19:12 /usr/bin/mail -> nail*
, which tells me that 'mail' is just a symbolic link to 'nail'.
So, I can read more about it by typing 'man nail' (although, it might also be available as 'man mail').
Note: In the above code, those are backticks (`), not single quotes('). Your output maybe be different: if you don't see an arrow (->), it means that your MUA is really called 'mail' and is not a symlink to anything else.
I thought that maybe the sent emails would go to another file or directory by default.
Isn't that the case?
I wouldn't think so, but it might be the case for your MUA.