I have Windows Live Mail running (or rather, stumbling) on Windows 10.

My problem is not that it sends emails to only part of a group list, but rather that it actually deletes addresses from that list randomly and without warning. For instance, one group had 48 names on it and is now showing only 33. The contacts still appear in the main list, but disappear from the group.

Microsoft, of course, no longer support Windows Live, and cheerfully admit they can't fix the problem.

Can anyone help me to keep all the addresses I put in a group in that group permanently, or at least until I want to delete them myself?