You are right on target. I was able to get my email up and running with help from dreamhost support!
I posted a screen shot of my advanced sending options on my website and here is what dreamhost support wrote:
"I'd be happy to help with this! So I looked at the screenshot and it
appears you have SMTP SSL on, which is only supported on port 465. SMTP
Auth and TLS are supported on ports 25 and 587, however SMTP SSL must
have an exclusive port because it's an SSL connection by default. In
order to get this to work, either override the smtp port to 465 or turn
off SMTP SSL and use 25 or 587. If you have any further questions about
this, please let me know!"
What I did:
I turned off the SMTP SSL option and then overrode the default port to 587.
Email is humming along like charm now!!
There is more on this on the Beginner's forum under a thread by the same name: