I can access , read , emails but cannot send?

I have Vista Home Premium , 32 bit , DL'd IE 8 because yahoo said it worked better with them .. when I try to send email I get the message "Please wait while your message is being processed" , so I wait and wait and wait , but it never sends. This started 2 days ago . I have dialup because nothing else is available here , yahoo has been slow with mail for quite some time now and that too is aggravating .. everything but yahoo mail loads and works just fine