wireless email problems

I have changed from plugging in my cable to a wireless connection. Everything works EXCEPT my email connections. I can access all sites except my email ones. I can be taken to the login pages of hotmail and yahoo but when I type in my username and password I just get nothing or error messages. I have tried using alternative browsers to no avail- same result- all sites are available (even MSN messenger) except the email. I have tested on my laptop which has a totlally separate modem and link and the email is still accessible there. Any suggestions- its driving me mad.