Hello all,
im running a linux computer as an email relay and gateway from our LAN to
our ISP with qmail as our mta. I didnt set up or use an own DNS-Server.
Instead we use the /etc/hosts file. All our clients are in this file of
course and etc/resolve.conf says: hosts bind.
All works fine until diald is running to bring up the dialup-connection when
it is neccesary. Without diald i can post emails via smtp from my
win95-outlook to qmail and it delivers the mail to the local homedir of the
user or via a catchall-alias to a relay-maildir for later delivering.
if diald is running this job suddenly didnt work anymore. The mails wont go
out of my outlook. Killing diald ... and all works fine again.
I discovered that the problem is, that qmail-smtp seems to do a dns-lookup
when a smtp-request comes in. This results in that diald brings up the
connection and if the dns isnt reachable in the hanging of the mails.
This effect appears even if i "telnet" on the linux-computer to the
smtp-port (entering at the commandline: telnet localhost smtp). I can
telnet-login to this, but the diald-queue is filled with dns-requests. And i
think there must not be a DNS-Request for "localhost", isnt it? All other
ports i tried (i.E. ftp) dont show up this behavior. So it MUST be
qmail-smtp who is the "bad boy".
Strange is, that this DNS-Lookup-Requests appear even if the mail is
addressed to a local user within our LAN or with an homedir on this
localhost.
As we dont want the connection to come up every time s.o. writes and sends a
mail (we want the mail collected and batch-delivered) i need to disable this
behavior of qmail-smtp or a configuration that works around this.
So my question is:
a) can i somehow disable the DNS-Lookup from qmail-smtp?
b) is there another way to workaround this annoying dns-requests?
Please help me soon if you can. I need the solution really urgent.
Thank you in advance for your good cooperation.
CYA
Joerg Toellner
