Windows Live Mail won’t send e-mail using little hometown ISP email address

I have read the forums and message boards on this and can't fix it. Using my email address given by our local ISP, we can receive but not send email. I've checked the servers over and over. Everyone keeps mentioning ports but I see no place I can edit the ports, even when typing our ip address in and looking at the router settings. Also WLM doesn't give an error message, it just sends an email back that says it wouldn't send, so they saved it in drafts, so please check if you had the correct email address and no oversized attachments. So I feel lost in how to solve this.