I’ve not written this part of the book yet, but what the heck, it’s good research.
Windows Phone supports multiple accounts of different types. But it treats each account type a bit differently.
As explained previously, everyone who uses Windows Phone will want/need a Windows Live ID. This is key to having a great experience, but it’s also required for certain phone features. So it’s sort of a no-brainer. But it acts differently than other accounts.
When you configure your primary Windows Live account on the phone initially, it connects to your contacts list, photos, and feeds. These cannot be individually configured. You can, however, later enable email sync if you’d like, from within Settings. And if you navigate to the Calendar app, you’ll see that Windows Live calendar sync is enabled automatically. But you can turn it off from there.
Note that, for the preview release only, syncing email, contacts, and calendars for multiple Windows Live IDs is not supported. This will be supported in the final release.
You use the Outlook account type to connect to Exchange-type accounts. (Why isn’t it just called Exchange then?) This includes Exchange Server, Outlook Web Access, and so on, but also any email account that uses Exchange ActiveSync (EAS) on the back-end. So you can configure Gmail this way, or the new Hotmail or MobileMe (presumably, I have tried either yet). Outlook accounts can be configured to enable/disable email, contacts, and calendar sync individually.
Yahoo Mail can be configured for email access only. The connection is automatic, but if you check the settings, it’s going through IMAP.
You can actually connect to Google/Gmail two different ways: Automatically, by choosing Google as the account type, or manually, by choosing Outlook (and then advanced) or Advanced Setup. Either way, you can configure which Google services to sync, and email, contacts, and calendar sync can all be enabled/disabled individually.
Right now, Facebook is the only social networking (i.e. non-email-type) account you can connect to via the Windows Phone accounts interface. It’s either on or off; if you connect to Facebook, it will sync contacts, photos, and feeds. There’s no way to configure this is any way (like, turn off contacts but leave the others on).
Other Account/Advanced Setup
Windows Phone also lets you manually configure any other email account types easily enough, assuming you know all the server addresses and other configuration mumbo-jumbo. Aside from manually configuring Google/Gmail as an Exchange-type account, I haven’t really played with this too much, but I’d imagine that non-Exchange-type accounts will be configured for email only.