I noticed this problem on my 4.9 box that my admin email account was not working. When I looked at the the /etc/virtual/ the hostname for the server did not have a folder and corresponding files. If you want to take a look at my setup to see what I am talking about it could just be us...I will email you with this thread as a reference.
--------------------------------------------------
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:
[email protected]
(ultimately generated from [email protected])
failed to stat /etc/virtual/host.domain.com/. (No such file or directory):
retry timeout exceeded
--------------------------------------------------
--------------------------------------------------
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:
[email protected]
(ultimately generated from [email protected])
failed to stat /etc/virtual/host.domain.com/. (No such file or directory):
retry timeout exceeded
--------------------------------------------------