Troubleshoot 10 common Exchange problems

1.Users cannot access server. – If you users can not access your Exchange system, but your system and Exchange services are running, there are several possible explanations. The first thing to check is that your network is responding properly. If users do have lost network connectivity, you will need to check their overall connectivity status, connectivity to other servers on the same switch as the Exchange server, also check the network controller in your Exchange system and verify that the system has connectivity to elsewhere on your network. Another possible reason for users not being able to connect to your Exchange system is if your Active Directory has stopped authenticating users. If your users cannot authenticate, then they will not be able to log into your Exchange system.




2.User’s messages are disappearing from their mailbox. – If messages are disappearing from users mailbox, one common cause of this is the auto archive feature in Outlook. This happens when the PST file being archived to becomes corrupt. To correct this you must find the PST, and run the ScanPST.exe tool (included with Outlook) to repair the PST file.



3.A user’s account was mistakenly deleted from Active Directory, and now they cannot access their mail. – If a users account has been deleted from Active Directory, their association to their mailbox is deleted. Normally, you can just right click the mailbox in Exchange System Manager and reconnect the mailbox to a new account. If this option is not available, you may need to run the Mailbox Cleanup on the Information Store containing the mailbox.



4.Outgoing mail is not being delivered, and is stuck in your queue. – If your outgoing mail is not being delivered, and is stuck in your queue, the first corrective action you should take is to restart your SMTP service. If this does not work, you should check your DNS resolution. Perform an nslookup (with type=mx) on your mail server, and see if you can resolve several domains you commonly exchange mail with. If you cannot pull MX records for those domains, then you should perform and IPCONFIG /FLUSHDNS to flush your DNS cache. If this does not work, then you will need to begin troubleshooting your DNS infrastructure.



5.Mail is not being delivered to a Distribution List – If you have one (or more) distribution lists that are not receiving mail that is being sent to them, you need to check that the group type in Active Directory has not been changed from the group type Distribution to the group type Security.



6.Mail to a certain user is not being delivered, and a trace shows it as stopping at the step “Submitted to Categorizer” – If you have a message that is not being delivered, and a trace shows that it never goes past the step “Submitted to Categorizer” it shows that Exchange is unable to determine what should be done with the mail. One common cause of this, is that the message is being sent to a users contact. If this is the case, delete the contact and recreate it. This will often correct the problem, as the contact has become corrupt.



7.Some users passwords are rejected when attempting to access your system through IMAP – If a users password contains a special ASCII character (such as ½), they will not be able to access IMAP. Passwords must contain only standard characters and symbols to access IMAP.



8.SMTP Service keeps crashing. – If you SMTP service keeps crashing, the first thing you should do is to empty your mail queues, then restart the service. Many times a corrupt piece of mail will cause the service to crash when it attempts to process it.   Reference  Link : http://www.techrepublic.com/i/tr/downloads/home/troubleshoot_10_common_exchange_problems.pdf