Hey team MailDoso had a massive outage across their servers (some of you might use it.)
Basically, without going into the full details a lot of their domains had a technical issue with sent them to spam.
So...they are shelling out a ton of money to fix all of these problems, and most likely will have solved them and turned the game around.
My advice, wait a month, ask around and do some small tests if you want to use them.
This happens with mailbox providers a lot and it stems the reason why we should always use mailboxes from different sources and not be reliant on one. I've made that mistake.