iPhone again - This time it removed an important email

For some reasons Apple iPhone keeps doing something or the other that does not let me settle down and love it. This time it deleted an important email - Just out of the blue. I was reading a yahoo email and accidentally it moved it to one of the other folders from Inbox. After searching a bit I found the email. I opened it and clicked the move icon and moved the email back to Inbox. Nope. Instead of moving back to Inbox it removed it. I spent hours to search on iPhone and email's web interface to find where that email was but could not trace it. No where to find. Thanks iPhone! With all your fancy bells and whistles you are proving to be a junk phone that I have ever bought - at least for me.