I just played with this for over an hour, and finally put the port as 587 and used the login method in smtplib and presto, it works for any destination.
I still think there are limits on the number of emails I can send per day, until I get a trusted sender designation from dreamhost, which is fine, we don't want dreamhost to get a reputation for sending spam.
This is as short as I can make it.
import smtplib, socket
from email.mime.text import MIMEText
msg = MIMEText('a message')
msg['Subject'] = 'the subject'
msg['From'] = 'EMAIL@MYDOMAIN.COM'
msg['To'] = 'SOMETHING@SOMEWHERE.net'
s = smtplib.SMTP('mail.MYDOMAIN.COM', 587)
s.sendmail(msg['From'], [msg['To']], msg.as_string())