My website, www.oparc.org, has userforms used in a couple different places. Right now, I cannot get them to e-mail me when there has been a submission. My e-mail, @oparc.org, goes through spamsoap, then into my companys exchange server. I've checked the logs for spamsoap and there has been no attempt to e-mail me. Likewise, I looked at the logs for the firewall and my websites IP has not e-mailed me.
So i tried to set up an outbound SMTP server that the server would route the e-mails through, but then i get "SMTP Error: Could not connect to SMTP host." when I use https://github.com/xeraa/silverstripe-smtp
Try just using the SilverStripe email API to see if you can send an email (i.e write a custom function to send a message through http://api.silverstripe.org/2.4/sapphire/email/Email.html) then it would be a Userforms issue. Make sure you've defined a from address.
Postmark is a good tool for sending emails without worrying about smtp etc.