SB welcome email not working with Wordpress 3.8.1


My plan is to use SB welcome email for new registration and password reset. But in wordpress 3.8.1 the standard wordpress message is send out to new users.

I've also deactivate all the plugins and still the SB welcome plugin is not working.

What other solution can WPMU DEV provide me?

Next questions is
I would like to use a professional SMTP service, otherwise my send emails will get in the spam box. What can WPMU DEV recommend me?