I use a sub account and my already read emails are being permanently deleted automatically after about 10 days. They are not going into trash bin, they are being totally deleted. According to the policies, the read email should stay in indefinately ??? any help out there on this. thanks
Personally I recommend that you don't EVER count on any WEBMAIL for your mail. Always use a client such as Thunderbird or Microsoft Live mail.
Any time mail disappears from the server, there's a pretty good chance there's some device pulling it off. This can happen even without you intending it to. For example, the default Verizon setup for a long time (and possibly still) configured Outlook automatically unless you were paying attention and unchecked the box during the install.
The easiest way to fix it is to change your password. Once the device(s) can no longer authenticate, the disappearances should stop.