This is exactly the same post I wrote about a year ago, and now I am facing exactly the same problem. Dreamhost appears to have upgraded their mailservers (and we know it was also painful during that time) and even then this issue has occurred. We didn’t even realise and spent hours fixing our clients individually before figuring the server issue.
"I am unable to receive ANY emails on my mailserver mail.cyno.co.in
There is no bounce or errors. I do not know how to access logs and dreamhost live support isn’t available for another few hours.
My business relies on email and seems we’ll be making losses today.
Looking at recurring email issues everyone has with mail on dreamhost, it seems like I made the wrong choice. Any quick suggestions are welcome before I can reach support."