The task analyze Gmail/Hotmail/Yahoo protocol and identify the protocol for setting a users' signature.
More specifically, what you need to do is first identify how to login to these services. And once the log in is successful, you need to find out how the requests look like for setting a users' signature.
Hhere is how I would approach this:
1) Create a yahoo account
2) Enable firebug or any other HTTP traffic monitoring tool
3) Login into your Yahoo account
4) Analyze the traffic to find out URL and the format of the login post request
5) Test using your scripting language of choice that to make sure that the login protocol you isolated works.
6) Repeat 5) for setting signature.
7) Do 1) to 6) for Gmail and Hotmail.
I can provide you with the login protocol for Gmail and Yahoo. I'm not sure about hotmail, but if I look hard, i could possibly also have it.
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