I have an LG Phoenix with Android 2.3 and I just recently did a factory reset, and now when I go to add my Google account, it won't let me add it. After I entered in my username (...@outlook.com) and my password, it says that "...@outlook.com does not use gmail". Then it offered me a couple suggestions to create a gmail account. I don't want a Gmail account. I don't understand why I need one when I've already got a Google account. I thought that would be enough info needed.
As noted in this question, there's no special hard requirement for gmail anymore.
<ics GoogleServicesFramework (or at least I tested version 2.3.7 that can seemingly only be found on some late-gingerbread stock ROMs) still expects that as "principal" one (ie use Play Store and GMS).
I guess like this shouldn't be too hard to solve by tinkering with the apk or accounts.db, but for the moment that's it.
Creating a totally new and dupe account, with your main "official" one as secondary (to keep stuff in sync) should work then. It's not really the most of simplicity or neatness, but if you don't want to dirty your account with gmail face, it's the only other option.