If somebody grabs control of your email account they will not only have some of your secrets. They will probably be able to grab access to all of your other accounts. They just do a password reset, the link goes to your email (which they control) and they are in.
This is because the underlying email products (IMAP, POP, and SMTP) are unencrypted and insecure.
So if you are using your smartphone email app, you are basically hosed if you use an unprotected hot spot.
A safer way to access your email while traveling is through a web-based interface, like Gmail offers. The connection is end-to-end encrypted. So there is little change of thieves stealing your credentials.
But remember that if your laptop has an email app (Outlook, Apple Mail, or your smartphone app) then it is still using IMAP/POP/SMTP and it is exposing you. Since these apps run int he background, they can still make you vulnerable if you are using an encrypted web browser based email session.
Basically: If there is an email client application on your device, you are going to be exposed on a hotspot, even if you are currently using a browser with encryption.