None of the fields in the db message cache remain unique!!!! WHY!??!?!?!

[paritycheck]

Hi guys, I was working on building a simple email tagging system for roundcube email.. but the thing is that for my tagging system I'm using a very simple procedure whereby I take a unique id of the object to tag and the type of object to tag as well i.e. email, contact etc..

Theres one HUMONGOUS problem Im facing right now with roundcube and its kinda what I stumbled upon accidentally. I noticed that neither the UID nor the incremental message_id remains unique for each message in a consistant way making it practically impossible to use these values in my simple tagging system.. like for example I noticed that once all the emails are added to the cache...if I click on an email to preview it - for some reason its deleted from the cache!!! And all of a sudden a new entry is made in the cache with a whole new message_id.

ANd not only that If I move a message from one inbox to another mail folder.. I've noticed that the entry is deleted and only an entry is made when I click on the other folder I notice that the new entry has been assigned a whole new message id as well as a new UID. To implement my tagging function I need that atleast one value be unique for all emails and be consistant throughout :-(. Is there a way to do this guys... I mean what do I have to do... any hints would be greatly appreciated!