|
Question/Problem: In log files I have
encountered the following error message: "stack connect fail". Can you
tell me what this error means and tell me why it happens?
Answer/Solution: If you have two NIC cards
(or if you use any internal-only IP addresses) it may be that IMail is
trying to send external mail out on an internal address. If that is the
case, you will get "MX Connect Fail" errors. (The internal NIC cannot
connect to external IP addresses.)
To correct the problem go into the registry to
the
HKEY_LOCAL_MACHINE\SOFTWARE\Ipswitch\IMail\Domains
key and
change references to the internal IP address to the external IP address.
(Stop and restart the SMTP service after a change.)
It may also help to set BindToIP as described in:
http://support.ipswitch.com/kb/IM-19990204-ES01.htm
If that is not the cause, then there is likely to be some
problem with DNS.
If you have "stack connect fail" messages then IMail was not
able to connect to any of the MX records (you probably see the "MX Connect
Fail" error messages also), so it went on to connect to the A record for
the domain and that also failed.
Below is the process that IMail
uses to find the destination host and IP address for mail delivery. Errors
at different points will generate different error messages.
The
sequence that IMail uses to resolve/deliver mail is:
a. check for the
host in IMail registry
b. check for the host alias in IMail
registry
c. check for the host in "WINNT\...\etc\hosts"
d. perform
an MX lookup for the host on the DNS server defined in Control Panel ->
IMail -> SMTP -> Domain name server
e. perform an A lookup (for
the MX record above) on the DNS server defined in Control Panel ->
IMail -> SMTP -> Domain name server
e1. if a CNAME came back on
e., then goes back to d. with the new response
f. asks the NT network
stack for an A lookup of the domain name
g. prints "stack connect fail"
on name
The routine above returns at any point in the sequence if a
correct answer is found. | 
kbheader.gif