How does an SMTP Domain relate to a regular Domain.

Posted on 2013-01-31
Last Modified: 2013-04-01
We have been having problems with users using Viewmail and reply's and forwarded messages getting stuck in outbox. Also some users have been experiencing loss of voicemails from outside callers. I talked with Cisco tech support and they said that we are not supposed to have Unity Connection and Exchange Server in the same SMTP Domain. He pointed me to a couple of links that are of very little help understanding this issue or finding a fix for it.

The first link provided a little information:

The second was a bug report CSCtx52609 with the following information.

UC: Need better doc on choosing SMTP domain

Symptom: Requesting documentation that will guide customer on what SMTP domain to choose for Unity Connection.

It is recommended that customer do not place UC in same SMTP domain as Exchange however there is no documentation to guide customer in choice.

Known issues have been documented that have been seen but requesting more documentation that might guide customers during installs.


UC 8.5.1
UC 8.6.x


Do not put UC in same SMTP domain as Exchange

My question is the SMTP Domain different than our primary domain? Or is it a part of the primary domain?

If it is part of the primary domain how do I go about setting up Unity Connection in a seperate SMTP Domain so that,according to Cisco Tech support, we can avoid these issues we are having.

Any information that would help me understand this problem or better understand SMTP Domains within an organizations primary domain would be greatly beneficial and appreciated.
Question by:BCUST
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Expert Comment

ID: 38847236
The first article posted relates to using a single inbox in Exchange for voicemail.
Generally, if you are using Exchange to store/deliver voicemail, you will never use the Viewmail feature.
I'm going to assume that you are simply using the notification feature that sends a user a message with a link to the voicemail.
Unity Connection is a IMAP mail server in its own right. The SMTP domain is used when sending outbound email. This should resolve to a dns MX record for Currently, your Exchange server is probably the only one with a MX record. Many receiving mail servers will do a reverse look up on the IP address of the sending mail server (your UCNX), and try to match it with a MX record, and drop it if it does not find one. It thinks you are an unauthorized relay host.
The easy fix is to have a separate MX record in DNS for your UCNX host, with a much lower priority than your exchange. Say for example your Exchange record has priority of 10, make the ucnx priority of 100.
That said, the "real" solution would be to integrate with Exchange to drop the complete voicemail into the users inbox, with attached .wav file. It does not have to be single-inbox, just "unified"..

The other option is to setup users with an additional IMAP account in their Outlook client, smartphone, what have you and point to the ucmx server on a public IP address.
I can help you with that if you want to move forward that direction.

Author Comment

ID: 38851323
That said, the "real" solution would be to integrate with Exchange to drop the complete voicemail into the users inbox, with attached .wav file. It does not have to be single-inbox, just "unified"..

We do have the voicemails coming in as an attached .wav file.
The sender shows up as Cisco Unity Connection Messaging System <> Off site messages have a subject line Message from Unknown sender (phone number)

We try to use Viewmail so the users can listen to the messages from within Outlook without having to open it in media player. However, we are having more problems than with just Viewmail.

I will take your response and show it to our server support team and see what they want to do.
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Expert Comment

ID: 38857810
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Author Comment

ID: 38860172

We do have an MX record for Unity Connection, however, the priority was not set correctly. We will be doing some testing today to trace the voicemails to see if they are leaving Unity and making it to exchange.

Author Comment

ID: 38861940
Correction: we only have an MX record for both of our hub and client exchange servers.

We did a test today and  left a voice message with the affected user and a non-affected user.
When doing Message tracking in Exchange we did not see the voice messages. After doing some research I believe it is because Unity Connection is not "sending" the voice mail as a message but rather synchronizing with the mailbox storage server and not the hub or the client exchange servers.

I believe from my understanding of what we went over today. Unity is integrated with exchange.

During testing we were looking at the https:\\<Unity pub ip>\inbox logged in as the affected user. When the voicemail was received it stayed for about a second or 2 then disappeared. Unlike a voicemail from within the organization which stays and shows up in exchange.

I have been told that we will not create an MX record for Unity Connection and we want to keep using single inbox.

Accepted Solution

BCUST earned 0 total points
ID: 39026139
We finally got a resolution to this problem. The issue ended up being a corrupted mailbox on the Microsoft Exchange server itself. We had to backup the data on the users end into a .pst file then completely delete the mailbox all together then rebuild a new mailbox for the user. we were then able to restore the users contacts and emails using the backup .pst file we had created.

Author Closing Comment

ID: 39036777
No one was able to provide the answer. We ended up contacting Microsoft to resolve this issue. I am posting this answer so anyone else with this issue can find a resolution.

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