smtpa.midco.net works.
I just wanted to throw in my two cents that I was able to send email from outside of midco's network after changing the server to smtpa.midco.net.
This must be a recent change. I had to help my dad out this weekend. He's not sure how long it hasn't been sending properly but I'm fairly sure that it was working with smtp.midco.net from an outside network earlier this year.
...And don't get me started on how much I hate Midco. Worst... ISP... EV-AR!
A few years ago, they actually tried to tell me that it was technically impossible to setup forwarding on their email accounts. When I called them on their BS and forced them to let me talk to a manager, they finally admitted that it was their policy to not forward email accounts due to "security settings" to protect people from viruses.
Yeah... Because forwarding from your crappy email server to my trusted Exchange server, (which takes the email off of your servers AFTER it's gone through your filters) is a security risk... Whatever, idiots.
Anyway, for that situation, POPCon (Big thumbs up for that, BTW) provided me with the workaround that I needed.
But I digress... Bottom line, Midco sucks worse than any ISP I've ever come across, but if you need to relay outgoing mail with your own VALID email account from an outside network, smtpa.midco.net will let you do what you need to do (for now).