Calendar app that supports email reminders

No, the built-in Calendar application does not have a default alert setting.

However, third-party apps can do it (and access the same calendars). For example, Quick Event (found here) looks like what you want.

Edit: If you're connecting an Exchange account or to a Google calendar via the Exchange setting, the Second Alert option is not available, because these systems do not support a second alert.

If you are not connecting via the Exchange setting you can access the Second Alert like this:

• On your iPhone, start Calendar.
• Navigate to the day that has your event.
• Select the event, which brings up the Event Details.
• Click the Edit button.
• Scroll down until you see Alert.
• If the event does not already have an alert, it will say "none" and you click "none" to add an alert.
• Once the event has an alert, you will see a new entry just below it called Second Alert. It will say "none" and just like the first alert, you can click on it to add another alert.