"Unable to establish a connection between WebEx and the mail server."

Question

Hi,
I installed Cisco WebEx and integrated with our Microsoft exchange server.  It showed server "UP".  everything's came up and working fine after that and sudenlly i found this message "Unable to establish a connection with the mail server.  Please recheck settings."
I went into the Mail Server setup to edit settings and now, it shows Server Down.  Do I need to do something on the MS Exchange 2010 or from webex server ??
Any help is greatly appreciated.  Thanks a lot!

Answer 1

Every 180 seconds, CWMS verifies the connection to the SMTP server by establishing a connection on TCP port 25 (SMTP) and then sending the EHLO command followed by the QUIT command. This check is also performed once when logging into the admin web page or when browsing to System -> Servers (where the status of the mail server is displayed).
If  this sequence does not complete successfully, the warning “Unable to  establish a connection with the mail server. Please recheck settings.”  will show in a banner at the top of the CWMS admin pages.
You  can verify the connection to the SMTP server manually by using “telnet  25”.
If you have access to the CWMS unix shell be aware that CWMS does not come  with the telnet command installed.
As an alternative, you can use this 3-lines script:
exec 3<>/dev/tcp/x.x.x.x/25
echo -e "EHLO\r\nQUIT\r\n " >&3
cat <&3
Replace x.x.x.x by the ip address or hostname of the SMTP server and save the script in a file, f.e.:
/* script saved in a file named ehlo */
[root@dchriste-cwms-adm1 ~]# cat ./ehlo
exec 3<>/dev/tcp/10.48.54.79/25
echo -e "EHLO\r\nQUIT\r\n " >&3
cat <&3
Then, execute it:
[root@dchriste-cwms-adm1 ~]# sh ./ehlo
The output should be similar to this:
220 *******************************************************************************************************************
250-confukdc.confuk.com Hello [10.48.52.110]
250-TURN
250-SIZE
250-ETRN
250-PIPELINING
250-DSN
250-ENHANCEDSTATUSCODES
250-8bitmime
250-BINARYMIME
250-CHUNKING
250-VRFY
250-XXXXXXXXXXXXXXXXXXXXXXXA
250-X-EXPS=LOGIN
250-AUTH GSSAPI NTLM LOGIN
250-AUTH=LOGIN
250-X-LINK2STATE
250-XEXCH50
250 OK221 2.0.0 confukdc.confuk.com Service closing transmission channel
Also, you can use this tcpdump command to see the conversation (replace x.x.x.x by the SMTP server’s IP address or hostname):
tcpdump -vXs 0 host x.x.x.x and tcp port 25
If you have HA, it is not certain which admin VM talks to the smtp server, so best to check both.
If you don't have access to the CWMS unix shell, best to span the switch ports and run packet capture.