[ILUG-BOM] OT: is imap protocol used by gmail and yahoo?

hello all, this may or may not be considered off topic. actually the subject line seams to be off topic but this is some thing to do with a program I am writing which needs to send emails out of the box. I want to know if imap is used by all popular email servers. I will need to send emails to gmail, yahoo, msn (unfortunately) and rediffmail. may be sify also but that's not sure. so when I write my program in python and asuming it is running on gnu/linux, should I program for imap given the above email servers? also do let me know what else will I need to have on my linux box, msmtp? or any thing else? I asked on the python list and they say nothing is really needed. thanks, Krishnakant