I wonder if some of you have found a way to share an iPad in a family and keep a reasonable privacy on the emails stored on the device (since there is nothing like a session management feature...)
Any tricks or ways to handle this?
The only trick is to actually go into settings app and delete the mail account by turning it off. Your password is still stored - just the data is flushed until you or the family goes to turn it on.
It prevents casual or accidental exposure of the mail contents in a similar manner to closing an unlocked door. It's a little better since your family will need to go poking to learn mail is off - especially if you leave enabled one account that has mail of a less private nature.
For meaningful security, you'll have to delete the account credentials and use webmail or enter it in only when you want access to the mail you consider private.
Another "trick" is to use a feature in gmail where it allows you to suppress certain mail folders from IMAP. This setting has worked for me on iOS to keep some archival folders from ever syncing to my devices (even though iOS uses exchange active sync to get the mail from gmail). You can see these messages through webmail or toggle the settings when you need to have them temporarily on your IMAP/exchange sync devices.
If a jailbreak is a option for you you can search for