my mail won't show after upgrading to 4.0.4
When chaging Android major versions, GB to ICS or ICS to JB or even GB to JB, its advised to do a full wipe, since many old files from the previous version might collide with the new Android version.

Since you haven't done it, I suggest you do the following:


Backup all your phone's data with either Titanium Backup or a Nandroid backup if you have a custom recovery installed.
Get your phone to recovery mode and wipe all data (factory reset). If you have a custom recovery you can wipe /system, /data and /cache.
Once clean, reboot in download mode and use Odin to update to 4.0.4 (or 4.1.2 if you have the international version GT-I9100)
Reboot and enjoy a clean installation of ICS/JB.