The thing is this is not a Flexi issue. There are no "settings" per se for email inside of Flexi. You will need to set up your email client properly first, then every thing else will work fine. I would start there. And your internet seems to be working fine. so that not the problem. Call the guy that set up the new internet access?
The installer doesn't have a clue, he just pulled cable and plugged in the new router. I remember filling in the information while installing flexi, just was hoping there was an easier way than re-installing again