encryption - tls - to connect to mail server
ssl - with xmpp server.
But this is the same whether I use laptop or phone.
The kind of security I am concerned more is phone device specific.
I feel pretty safe about my IM and emails, but I know that carrier can track my location, and may be even listen talks by using phone's microphone.
And this is done by using gsm chip, that's why I am concerned about gsm part.