Well I am must say I am not happy with Dreamhost emails.
I send two emails to the Dreamhost team about a critical problem.
Moreover I find out that I was not the only one in that situation : https://discussion.dreamhost.com/thread-139136.html
I use somes Q2A Forums (like stakoverflow) on my websites (one is odlg.org) and I ask my users to confirm by emails. But users with hotmail, outlook (and maybe wanadoo), did not receive my email. After 4 days I receive an answer from Dreamhost team, that everything was ok but it is not.
And if I try via SMTP i got this :
Question2Answer fatal error:
Could not send email confirmation
require() in index.php:31
require() in qa-index.php:175
qa_get_request_content() in qa-page.php:794
require() in qa-page.php:207
qa_send_new_confirm() in qa-page-confirm.php:54
Now I am stuck because I have 10 forums, and they are not working with that, and if I disallow email confirmation, I will be spam for sure. Everything was working fine with emails in my other webhosting.