I am having trouble with users logging in and registering. When the form is submitted it kicks the user back to the homepage without being logged in.
The registration does the same thing.

Even when adding users from the admin, activating it manually, it still does not allow the user to login on the front end.

@Laztrad
Enable error loging and then review your log for possible errors.
Make sure to setup mail server properly.

Email server is set up correctly, all error logs are enabled but i´m not getting anything on the logs.
I have tested the mail server and its all functional.

Its not registering the user

@Laztrad
Without log, nothing can be investigated.
I would also recommend you to go into database and try to create 1 user, if it works OK in there.