We are still actively working on the spam issue.
I suggest Openmailbox to be removed from the recommended providers. I have been an Openmailbox for just about over a year and I can say that the service is terrible. They go down regularly, there's no feedback at all, there is basically no reason to use it. Right now no one can receive or send e-mails. If you do try to send a @openmailbox.org something it will give you the following error:
retry timeout exceeded. See
https://www.reddit.com/r/openmailbox/ and https://twitter.com/hashtag/openmailbox?f=tweets&vertical=default for more complaints.