mail disappearing

[Guest shepperd]

I am bewildered by this. In spite of carefully checking that mail is never deleted from server, both on the server and in my pc mail prog. (Thunderbird) and on the Tab... after 48 hours or so, the mail in the in-box disappears without a trace! This happens both with the default Email app. and Gmail. Anyone have this issue or a solution Please? I just don't get it.