Lately I am getting a lot of mail delivery fails like 20% of the time.
It used to be less, then some domain on our shared hosting was blacklisted in spamhouse and all emails couldn't be delivered.
The problem was sorted and our IP isn't blacklisted any more, but the delivery rate is strangely low lately.
So I am asking if your IP is delisted from spamhouse can you still be affected by the previous listing?
Also what can be learned from a mail delivery fail?
This is the error I'm getting:
A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed: