Can receive, but not send emails

Starting a few weeks ago emails sent on my Windows 7 laptop using Windows Live Mail would receive emails, but outgoing ones were not sent. Everything was working fine up until then. Emails were in the "Sent Items" folder for WLM , but did not make it to the ISP mail server. I have spoken to my ISP, Road Runner, multiple times along with Microsoft support going to second and third level support. I can send and receive using going directly to the Road Runner Webmail server. The problem occurs on multiple machines and also when running Outlook and Thunderbird. Neither Road Runner or Microsoft admit that it is their problem. I am using 25 for my outgoing Port and have tried 587. Neither work. I will also mention that when I add my Gmail account to Windows Live Mail and send from that account it works fine for sending and receiving. I know an obvious answer would be to switch all my email to the Gmail account, but I would like to solve this problem first.

Tech Support Guy System Info Utility version 1.0.0.2
OS Version: Microsoft Windows 7 Home Premium, Service Pack 1, 32 bit
Processor: AMD Turion Dual-Core RM-75, x64 Family 17 Model 3 Stepping 1
Processor Count: 2
RAM: 2814 Mb
Graphics Card: NVIDIA GeForce 8200M G, 256 Mb
Hard Drives: C: Total - 294058 MB, Free - 207067 MB; D: Total - 11181 MB, Free - 1988 MB;
Motherboard: Wistron, 303C
Antivirus: Microsoft Security Essentials, Updated and Enabled