Over the past couple of days, I have noticed that emails are randomly disappearing from my Trash Folder.  On Tuesday 15 had disappeared, Wednesday another 21 and Today 18 had disappeared.  It's not like the oldest ones are disappearing, it seems to be random dates.  No one else has access to my email, so it's not like someone else is going in and deleting them.   I looked in Preferences and can't see that there is a setting that says they auto delete after so many days.  Emails in the Junk Folder do automatically delete after so approximately 10-14 days.  Does the Trash Folder have a setting to auto delete?  Occassionally, I delete an email, and then want it back or need to refer to it again.  Since they are automatically randomly disappearing, that makes it impossible to do now.  Why would they be automatically disappearing?

Update - Last Monday I had 250 emails sitting in my Trash Folder, tonight there is only 138.  During the past week, I have purposely not deleted any emails from my Inbox in order to see how many are disappearing.  What happened to them?