Hey omsaj,
I posted the below in another thread (https://discussions.apple.com/thread/5452367?answerId=24670895022#24670895022) but just found yours, which is more recent. I have same problem. The fix in the other thread was to do a factory reinstall -- really not something I want to do.
____________________________
Hey folks,
I cannot find a more recent thread discussing this issue, but I am having the same problem in both Mail and Messages App in version iOS 7.0.4. It began about 3 days ago; I don’t recall doing anything out of the ordinary.
Here is 30 second YouTube vid of issue. I couldn’t embed in my reply. http://youtu.be/bNw_JsXkO4Q
Put simply, when selecting one or more Mail or Messages items iOS automatically deselects them in a second. Also battery life is now nonexistent—phone now goes from 100% to 0% in about five hours.
Deleting all email accounts and adding back did not fix, nor did Home + Power button reboot.
In another thread it was mentioned that a Factory Reset (complete erase and set up as new phone) worked (see here: https://discussions.apple.com/thread/5358539?answerId=23165916022#23165916022) I REALLY need to avoid this option.
Any other thoughts would be very much appreciated.
Best , JJ