Sigh. We hate to bring this info, but for those who hate the "feature" in Windows Mobile HTML email, whereby images have placeholders until you "agree" to download won't be pleased.
Evidently Windows Phone 7 uses the same approach, requiring an extra step and unsightly image placeholders until you sync up again. For those curious, this unique method is not present on the iPhone nor Android (Edit: Actually, you do have to hit "Show Pictures" on Android), both of which automatically just show the images.
The reason Microsoft chooses this system is security: opening an HTML email with inline images that is potentially malicious can send back information to the originating servers, hence the extra step.
We get that and totally like this ability as we understand the needs of enterprise can run pretty high. But we want it as AN OPTION not a default/you have no choice in the matter feature. Fact is, Windows Phone 7 is a consumer phone at this point and should therefore make email as transparent as possible--why not just give a simple initial warning sigh and give the use choice?