"This message was created automatically by mail delivery software.
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:
retry time not reached for any host after a long failure period"
And follows the content of the notice.
Host informed me three days ago to change the current nameservers with some new ones. I haven't change them yet, is this possible to cause this problem?
There is a big problem because many members get informed by email notices for replies, watching threads, etc and when they see that they have posts without noticing they are complaining.