Why does my email disappear on my ipad?

My husband had this problem on his iPad and I solved it by going into Settings, then Mail, Contacts,Calendars. Under Accounts I chose the email account which was losing mail and in the next box that came up, I changed 'mail days to sync' from 3, to no limit. His missing e mails reappeared.

This happened to me too when I started using my Ipad and downloading email from my POP email account. I performed some tests to prove a theory and that is that using POP on the IPAD makes the email application "Mirror" the mail account on the ISP server. So what that meant is that when I downloaded my emails to my laptop - I had that email package set to delete the emails from the server after download. SO...since it appears that the IPAD mail app "mirrors" what is on the server - it sees that there are no emails on the server so it removes them from the IPAD mail innbox - effectively "mirroring" the server. SO to fix this, I set my laptop mail application to leave my email messages on the server for up to 30 days. I expect that after 30 days my Ipad email will disappear again. I guess I can live with this but think it would be a good fix if Apple could figure out what the other POP compliant email packages do to keep from "mirroring" the email server account. I also use a droid phone to download my emails from the same server and this disappearing act never happened with either the Droid default mail app nor with the 3rd party Droidmail application.

To fix the disappearing act - change your settings in your other POP compliant mail application to stop removing emails from the server. Hopefully Apple will try to work out a change.

Phototinman