Writing and reading emails in Kannada
From Kannada l10n Wiki
Writing and reading emails on Kannada is as straight forward as it gets since Unicode is supported on most mail clients and on-line email services. But some of them are yet to support Unicode fully, so here's a page that would help you see Kannada on your email if you're not seeing it yet.
Gmail
Gmail has very good support for Unicode. Emails in Kannada should appear fine on Gmail, but if you're getting garbled text, Consult Documentation on enabling Kannada on the Operating Sytem you've installed.
Rediffmail
Rediffmail might need you to set encoding on browser manually to utf-8. (Fact check needed on this one)
Yahoo mail
Yahoo mail supports Unicode, but at times encoding at Yahoo groups is destroyed if the email is in Unicode. (Fact check needed on this one).

