Q: distributiongroup in mail

Set up groups in the Mac Contacts app.

Mac Basics: Address Book - Apple Support

You can also set them up on your iPad but it is easier on the Mac and then just sync them to the iPad. Syncing should be automatic if you use iCloud Contacts on both devices.

http://email.about.com/od/iphonemailtips/qt/How-To-Set-Up-Contacts-For-Group-Mai ling-In-Ios-Mail-For-Iphone-And-Ipad.htm