My mails on iPad disappeared!

I was using Mail app that came with iPad for accessing Verizon's mail server via pop3 & smtp for long. I changed password for my Verizon's account today, so did the same thing in Mail app on my iPad. As soon as I connected Verizon's mail server, all of my old mails (both inbox and sent) on my iPad disappeared. I didn't change the account name but did just its password.

Any way to recover my mails? I'm shocked...

Any suggestions will be highly appreciated.