Hello Alexander,
Yes, it is possible to use separate ringtones for your e-mails and texts.
To check which ringtone is used for your incoming texts, open Messaging, press
the Menu key (bottom key to the left of the five-way navigation key), arrow
down to settings, select this, arrow down to Notifications, select this, arrow
down to Select ringtone. You should hear which one is selected. Make sure
Mute is off.
there will be a separate setting for whichever e-mail app you are using for the
ringtone for incoming e-mail.
I hope this helps.
Best wishes,
Clive Pallett