So that confirms it. On the rules which are set up to be client-side only, the rule is applied BEFORE the message is sent, resulting in a draft being saved, whereas the server-side rules process correctly.

The only problem, is that I tried to replicate this issue, and had no problem. I set up a client-side rule by going to Rules (in the ribbon) > Manage Rules & Alerts > New rule and set it up so that emails to my gmail account would be saved to (first) drafts, then a custom folder I created for this purpose. They seemed to save correctly with no [draft] tag.

When you say "personal folder" it is still attached to the profile correct? As in it's a sub folder underneath your inbox for the same profile?