From my point view you should never disclose your personal email to anybody yo do no not know but its not really realistic sometimes. We do share to be honest. We all get emails from people we do not know but if yo have updated anti-virus or spam filters installed your system you are somehow is bit safe, not entirely.
1. Mostly emails are regarding Prize winning or inheritance related where senders will be asking you to send your personal details, bank account number, sort code etc to them so they can proceed with your million dollar deposit. Basically these are known as Identify theft.
2. Banks or any other financial institutes will never ask you for your personal details over the email.
3. No verified entity will ask for your birthday over the email.
4. If you win something you will get a certified letter at your home(Although still its better to have verified before any transaction).
5. If someone send a email to click on the link to reset your password , do not click.
6. No one from Pakistan or Nigeria wants to know you and give you money.
7. If there is typing error in the email then beware , it could be a fraud.