421-Service is not available error

What else is on the machine? Problems like this are usually caused by a third party application, not Exchange. I am not aware of any problems with the security updates released last month, and if there was an issue I would have expected them to occur immediately, not almost a week later.

Simon.

421-Service is not available error ??? is this what the users get when trying to access ur exchange servers ???

Exchange server is also a domain controller (I am planning to demote it) and there is also Symantec AntiVirus Server Corporate Edition 8.1

Yes, the exact message is:
421-Microsoft ESMTP MAIL Service, Version: 6.0.3790.1830 ready at  Service not available, closing transmission channel

http://support.microsoft.com/kb/872950

A quick note on your comment about Exchange being on a domain controller.
Don't demote it while Exchange is on the machine. Changing the role of the server while Exchange is installed is not supported and will probably break Exchange.

Simon.

Vahik, I already checked this - I received the hotfix but it says that my running version is more recent and cannot update it. My smtpsvc.dll is 6.0.3790.1830 - 24/03/2005 and from hotfix is 6.0.3790.196 - 21/07/2004

Sembee, I took a risk and demoted the Exchange this morning. Then made the AD integrated zone as secondary on the Exchange. For now everything works. I will see when will be the next stop of SMTP working. The last one was yesterday afternoon after 27 hours of proper work.

this is the second time i have seen a DEMOTION has fixed an exchange problem....which points to active directory problem......either FSMO roles got mixed up(dcpromo in multi DC environment alocates FSMO roles to the remaining
DCs) or it could have been DC machine password  corruption which could have been fixed by NETDOME utility or maybe a demotion..... or it could have been a DNS issue....

well all it matters now is the problem is fixed.....which  is very important ....

since Pdranov fixed his or her own problem i will have no objection for a refund of his\her points....of cource if sembee had no objection.....


you filks take care and good luck...

Unfortunately demotion doesn't fix the problem - may be it fixes some other problems (like quicker restart of Exchange server and lower load of the server) but this morning the SMTP problem appeared again. So I am waiting for other suggestions (may be this is another bug/security hole in MS products which somebody exploits against our Exchange)

Most "problems" with Exchange are not caused by Exchange or Microsoft at all. They are caused by third parties. The prime causes being antivirus and increasingly, antispam applications. I have seen many machines that have problems, remove the AV (which is the first thing I do/recommend) and suddenly the machine is behaving itself.

Simon.

Although Symantec AntiVirus Server is running on this server for 5 years without such problems I will try to disable File system real-time protection. If this doesn't work I will uninstall it and will inform you about the results.

I tried to automate the restart procedure with following files but when things reach the end when SMTP service has to start it remains in Starting state and never starts. If I do things manually (first stop all virtual SMTP servers, then stop SMTP service, then from IIS manager Restart IIS and finally start all virtual SMTP servers) SMTP service starts. Here are the files:

script.bat - scheduled to start every 1 minute:
----------------------------------------------------
@echo off

type test0.txt |nc 192.168.0.21 25 > test.txt

for /f "Tokens=1" %%a in ('type test.txt') do (
echo %%a
if not "%%a" EQU "220" (
      date/t>>smtprestart.log
      time/t>>smtprestart.log
      echo %%a>>smtprestart.log
      call srvstop.bat SMTPSVC
      call srvstop.bat MSFTPSVC
      call srvstop.bat W3SVC
      call srvstop.bat HTTPfilter
      call srvstop.bat IMAP4SVC
      call srvstop.bat POP3SVC
      call srvstop.bat RESVC
      call srvstop.bat NNTPSVC
      call srvstop.bat IISADMIN
      call srvstart.bat IISADMIN
rem      call srvstart.bat NNTPSVC
      call srvstart.bat RESVC
      call srvstart.bat POP3SVC
      call srvstart.bat IMAP4SVC
      call srvstart.bat HTTPfilter
      call srvstart.bat W3SVC
      call srvstart.bat MSFTPSVC
      call srvstart.bat SMTPSVC
) else ( echo OK )
goto :eof
)
echo 1 line - OK

test0.txt
---------
QUIT

srvstart.bat
-------------
      echo Service %1 starting>>smtprestart.log
      sc start %1>>smtprestart.log
      CHOICE /N /C Y /T 5 /D Y >NUL
:2
      sc query %1>1.txt
      find /C "RUNNING" 1.txt>nul
      if errorlevel 1 goto 2
      time/t>>smtprestart.log
      CHOICE /N /C Y /T 50 /D Y >NUL

srvstop.bat
-------------
      echo Service %1 stopping>>smtprestart.log
      sc stop %1>>smtprestart.log
      CHOICE /N /C Y /T 5 /D Y >NUL
:1
      sc query %1>1.txt
      find /C "STOPPED" 1.txt>nul
      if errorlevel 1 goto 1
      time/t>>smtprestart.log
      CHOICE /N /C Y /T 50 /D Y >NUL

When I do things manually IIS manager remains unresponsive (I have to kill it) but does what is needed. Nobody feels that there was a problem. Do you know how exactly IIS manager restarts IIS, how to do the same with vbscripts/bat files and also how to stop/start SMTP virtual servers from vbscript/bat file?

There was another fail of SMTP service today after disabling Symantec AntiVirus Server service. Now I will completely uninstall it.
I tried another approach to restart SMTP which was successful: stopped all virtual SMTP servers manually, executed the above scripts for restarting IIS and started all virtual SMTP servers manually. So I need only a way to stop/start virtual SMTP servers from vbscript/bat file.

Uninstalling Symantec AntiVirus Server didn't help. Today first virtual SMTP server did't start. In event log there was:
Event Type:      Error
Event Source:      smtpsvc
Event Category:      None
Event ID:      418
Date:            12/12/2006
Time:            09:09:23
User:            N/A
Computer:      BGVA-S03-EXCH01
Description:
Virtual Server 1: SMTP server cannot read metabase key MailPickupDir.

For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.
Event Type:      Error
Event Source:      smtpsvc
Event Category:      None
Event ID:      418
Date:            12/12/2006
Time:            09:09:23
User:            N/A
Computer:      BGVA-S03-EXCH01
Description:
Virtual Server 1: SMTP server cannot read metabase key MailQueueDir.

For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.
With IIS metabase editor I found out that there is nearly nothing for the first virtual server - only 5-6 keys. I rewrote nearly all keys from the second virtual server and it started. May be some of these keys were deleted and this was the reason for SMTP failure. We will see later.
So I have few questions:
1. Why I could see virtual SMTP server configuration when it was not in IIS metabase (is this info also in AD?) ?
2. If yes, why it stops to be copied to IIS metabase, and worse, deleted from there?
3. How to make keys in IIS metabase which do not have names (ID 49875, 61536 and 61537)?
4. When I try to edit AdminACL (ID 6027) key and try to add a new user or group I receive:
Application Error
An error occured:
Object reference not set to an instance of an object.
Do you want to continue?
Yes   No
If I click No IIS metabase explorer closes, if I click Yes it stops responding and I have to kill it from Task manager

As I can see reinstalling IIS will take too much time. For now I created a new SMTP virtual server with same settings as the first one and stopped the first so that I have now correct keys in the metabase for the new server. Will see if this will help.

SMTP didn't stop working for 6 days. I think the problem was solved.