I see a permission denied error. Where are you launching the previous command from?
Couldyou also launch this command?
ssh -T -i ~/.ssh/id_rsa email@example.com
If it fails, then run this one:
ssh -T -vvv -i ~/.ssh/id_rsa firstname.lastname@example.org
This should help us see more debug information about the issue.
Javier J. Salmerón