Sounds odd…
You may try rebooting into safe mode and see if that helps in any way for troubleshooting (like for mail app in case you use the integrated one).
Long press on/off button → reboot → long press system → safe mode
(Be prepared though that all app icons on the homescreen will probably be mixed up after booting again into normal mode afterwards)
I have no other idea on that matter for now, maybe others do…
What was your OS version before the update, can you still tell?
(@Manoj can you move this thread to the 3.7 feedback thread, it seems to belong there and might get more visibility)