Dropped emails saved in in box

[Android Question]

I have a Samsung Galaxy 3. I leave some emails in the in box (tracking numbers for shipments, registration verifications, etc) for future reference. Why do these continually drop out after just a couple of days and where do they go? I'm not able to find them in the Trash folder, they just seem to vanish. How do I retrieve them?

 

[Rukbat]

Who's your email provider and is it a POP3 or an IMAP account? What email program are you using?

 

[Mann1967]

It's a hotmail account.