the mail server being used in my office is qmail. now i have received some complains from people that they are getting time outs while sending or receiving mails in their email clients like microsoft outlook. is there any chance that the problem lies on server side. if yes then what can be the possible problem.

Timeout problems could be generalized connection issues as well as configuration issues. The first place I would look would be in the log files for Qmail. I would search on the user's ID if possible to see if there are any warnings or errors. If you can, try to get a date and time of occurrence from one of the users to help refine your search. See if the logs are even showing that they made an attempt to connect to the mail server.

The logs are showing that everything is working fine.The logs are showing that there is absolutely no issue as far as logging is concern.I came to know yesterday that one of the user has problems in outlook express, but i don't know about the other users.So what to do next

What do you mean by the logs are showing that everything is working fine? You have a client that claims that they aren't able connect to the mail server. Are the logs showing that they are making a connection? Your description sounds like they are not showing the connection because otherwise I would expect an error.

If this is the case, while they are experiencing problems, have them 1: ping the mail server both by IP and name and see if they have a basic connection. 2 - perform an NSLOOKUP up on the mail server to see if they have a DNS problem where they can't resolve the server, 3 - try to telnet into the server on port 25 and see if they get a response at all. Have the connect and possibly enter some HELO information and then exit. This should create an error entry in your mail logs. You should verify. This will help rule out a network issue in which case you can focus on the application and its settings.

Well I am sorry that I am unable to convey my problem properly. What I want to say is that there is no problem in connection between the users and the server but after 2 or 3 days we receive calls from the different users that they are having send and receive error in outlook for sometime. The monitoring of logs is done on daily basis and the logs confirm the connections of the users.

While the user is having apparent connection issues, that seem to only be on their end, have them do as I suggested in my previous post:

In order to figure out what is happening, you will need to get some diagnostic information. The timeout could be caused by either a network connectivity issue, which would explain the intermittent nature. Such an issue could be DNS related and I would have them perform the NSLOOKUP a couple of times. It could be caused by a protocol or port mismatch in their settings. It could even be that they are being blocked by a proxy or a lousy ISP policy somewhere.

Consequently, one of the first things to determine is while they are experiencing problems is if they are able to connect to the server at all or not. If not, you need to find out where the offending device is. Trying a Tracerout and trying to Telnet into the mail server will help in this regard.

yes the issues seems to be on the user end. thanks for moving along Noway and sharing your experience