How Long Is Too Long To Keep Email Conversations?

Seriously, when is it too long to keep an email conversation?  I am not talking about business conversations that one uses in there daily log but personal conversations.  I have the most silliest and shortest conversations ever from all my friends and family members in my personal email.  I am talking from like 2008 or before.  Help me!  Do I just trash those conversations as if I am trashing memories?  I don't know?  I don't ever go back and reread them.   I do want to reduce the ridiculous email clutter.  Help!!  Please give me your opinion.  It is rather odd that I have this little bit of inbox clutter since everything else about me almost OCD organized.  On the brighter note I do have them organized in folders, but honestly that is just as gross!

Dearest Rhonda Feltman, I do need your response on this one!!  Aunt Shirley and Allison Lemp you better offer up too!!

~ With Angela O'