How safe is It when I sent an email on my iPhone?

I want to send an email to one of my friends but her roommate does not like me so if I sent an email on my iPhone using a Starbucks Wi-Fi could they get my phone number and if they track the IP would it just head to Starbucks?

I don't think someone would go to that extent just to see your email hunny! Unless she has a lot of spare time on her hands even then she would have to be some sort of mobile hacker there's no way she can see anything you sent unless you show her!

No they can't track your IP.