I have a problem with my server. It started yesterday as a DNS
problem. I began receiving console messages that sysquery could not
find A.ROOT-SERVERS.NET....etc. As we were running a very old
version of BIND I decided to update it straight away. This was done
and as far as I can tell BIND is working fine (but I wouldn't rule it
out).
Mail had been sluggish while this was happening which is to be
expected but the performance of email remained slow even after the
DNS problems were removed.
I have tried telneting to the server on port 25 and it is taking over a
minute for the helo to appear. `netstat|grep smtp` shows that the
connection to the server is instant.
Incoming messages are piped to pop and clients are able to retrieve
mail from their pop mailboxes without any delay. However outgoing
messages are taking a v. long time to leave the client desktops.
My exim conf does have some DNS related options, though I have
commented many out now to try to eliminate DNS problems.
#host_lookup = 0.0.0.0/0 temp removed
receiver_verify
headers_sender_verify
sender_verify
sender_verify_reject
rbl_domains
I am running out of ideas and can not think of an reason for this
delay except perhaps the new DNS server is slower at resolving
addresses than the previous version. Has anyone an idea what might
be causing this? I have tried to increase the debug level to 8 and
send HUP to the processes but I can't seem to get an more
information than I already collect in my logs.
Any help or ideas would be appreciated. I am going on holiday this
week :-) but I need to have this sorted before I can go. :-(
