FlockMail lets you easily forward your email to a different ID. If you have your personal email account that you would check more often, or if you want emails from all your email accounts into a single email client, you may set-up auto-forwarding to enable this.
You can set-up auto-forwarding for your account by clicking on the Gear icon > Preferences > Forwarding.
By default, a copy of the email is NOT saved in your inbox, but this can enabled. You would then receive a copy of the email in both the email IDs.