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New Member

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


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!

Cisco Employee

"Unable to establish a connection between WebEx and the mail ser

Hi Ali,

The simplest way of configuring this is to not use TLS nor Server Authentication. You can just configure Anonymous access and ensure your Exchange server can relay messages coming from CWMS. A decent document that you can refer is:

If your Exchange server can receive e-mails from CWMS and send them internally, your receive connector should be fine as well as the configuration on your CWMS server. You would need to look into your external connector and see what needs to be configured to allow relaying the messages from CWMS machine (IP address) to the external domains. For relaying in Exchange 2010, command line commands can be found here:



New Member

"Unable to establish a connection between WebEx and the mail ser

hi to all..

the same things happens here..

also exchange..

cwms 1.5..the latest MR3..

"Unable to establish a connection with the mail server. Please recheck settings"..

this message pops up and vanishes from time to time..

at that time also status in mail server status on cwms admin flaps from up to down..

we've moticed that after some time..

the thing is that we can send e-mails from cwms to internal and external users..

but what we've noticed is that not all e-mails go through..

it's like that for following situations:

1. where we're opening new user account and ithey need to get "change password" e-mail from cwms

so..then we deactivet it and activate it again in order for cwms to re-send the e-mail..and then user gets e-mail..

2. when user is opening meeting..initially invitee ( although ) external ) doesn't receive e-mial..but when we resend it from meeting pane it does recieve it..

we thought it could be some spam control on e-mail servers, but there weren't any..

so, we kind of link that "flappin" state of mail server status and alerts on cwms admin portal with the facts that some e-mails come througha nd some not..

maybe, cwms doens't even send e-mail when it "detects" no connection to mail server..

the strange thing is that we don't have situation that it's not working at all..

the fact is the we have "Unable to establish a connection with the mail server. Please recheck settings." message..

and the fact is that some e-mails come through and some not ( to the same  receipients )..

any thoughts?..

this way we have unusable and unreliable system..



New Member

"Unable to establish a connection between WebEx and the mail ser

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 


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/

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 ******************************************************************************************************************* Hello []

















250 OK

221 2.0.0 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.

New Member

"Unable to establish a connection between WebEx and the mail ser

hi dirk..

thanx on your detailed t-shoot guide..

how can i get access to CWMS unix shell?..


New Member

"Unable to establish a connection between WebEx and the mail ser

Only TAC can create a unix shell account.

New Member

Hello gents,How did you ended

Hello gents,

How did you ended up with above issue.

I am facing exact same issue in CWMS 2.0 and need urgent help.



Cisco Employee

Hi,Is this a new deployment


Is this a new deployment or existing deployment that stopped working?

What is the size of your deployment?

What exact version are you running?

Kind regards,


New Member

Thank for quick reply Dejan

Thank for quick reply Dejan,

Its existing deployment that stopped working all of the sudden.

We have 50 User license.

Exact version is cwms




Cisco Employee

Hi, So your Mail Server needs


So your Mail Server needs to accept connections only from your Admin VM. I am not sure if you use TLS or just plain SMTP, but port 25 should be opened between CWMS and Exchange server.

If this is not working, you would need to reach out to TAC to create Remote Support Account and collect logs manually from the system (as e-mails with log download links cannot be sent out). 

Most likely there is an issue with connection to the Exchange server. 

You can try the basic putting system in and out of Maintenance Mode, but if that doesn't resolve the issue, we would need to analyze the logs.


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