SMTP Doesn't Support Authentication

I have a second generation iPOD Touch (32 GB) which can receive e-mail over Wi-Fi but can't send e-mail over Wi-Fi. I get the following error messages:"smtp doesn't support authentication; or "smtp account verification failed"; or "the connection to the outgoing server [insert server name here] failed." I have deleted and re-entered the information for my mail account numerous times but that has not helped. I have even "reset" the iPOD. What am I doing wrong in setting up my mail account which prohibits it from sending e-mail on Wi-Fi? I have the latest version of iTUNES so that is not the issue. Is this a port problem? My outgoing server port is set to 25 and my incoming server port is set to 110. My SSL setting is set to off. Also I am using password authentication. Any suggested "fixes" will be greatly appreciated.