svillardi
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Comcast email not going to domain with co-existent 2003 and 2010 Exchange servers
I am migrating an email server from SBS2003 to Exchange 2010. (I know it's old.) In testing co-existence with the old server, I have migrated 5 users from the old 2003 to the new 2010 server. These two servers are behind a firewall, with one external IP address. Migrated users are receiving email. Mailboxes on the old server are also sending and receiving fine.
However, when someone from comcast.net sends an email to user1@domain.com on the old server and user2@domain.com on the new server, comcast.net never sends the email. I have tested this on their portal, and from Outlook. I have tested email from a gmail account which works fine.
I am getting temporary and permanent connection errors from comcast.net.
While I am trying to work with Comcast, is there anything I can do to determine what the cause of this issue is?
However, when someone from comcast.net sends an email to user1@domain.com on the old server and user2@domain.com on the new server, comcast.net never sends the email. I have tested this on their portal, and from Outlook. I have tested email from a gmail account which works fine.
I am getting temporary and permanent connection errors from comcast.net.
While I am trying to work with Comcast, is there anything I can do to determine what the cause of this issue is?
Please post the exact errors you are receiving.
Sounds like a Comcast DNS problem.
I've had users in the past have emails get lost because of ghost DNS issues with the ISP(Network Solutions).
Call up Comcast and see if they can duplicate the issue.
I've had users in the past have emails get lost because of ghost DNS issues with the ISP(Network Solutions).
Call up Comcast and see if they can duplicate the issue.
within COMCAST what MX records do they have for your mail servers ?
ASKER
Thanks for the replies.
Here is one of the NDRs:
Reporting-MTA: dns; resqmta-ch2-01v.sys.comcas
Received-From-MTA: dns; resomta-ch2-07v.sys.comcas
Arrival-Date: Wed, 27 Feb 2019 20:05:41 +0000
Final-recipient: rfc822; user2@domain.com
Diagnostic-Code: smtp; Connection timeout
Last-attempt-Date: Fri, 01 Mar 2019 06:24:14 +0000
Here is one of the NDRs:
Reporting-MTA: dns; resqmta-ch2-01v.sys.comcas
Received-From-MTA: dns; resomta-ch2-07v.sys.comcas
Arrival-Date: Wed, 27 Feb 2019 20:05:41 +0000
Final-recipient: rfc822; user2@domain.com
Diagnostic-Code: smtp; Connection timeout
Last-attempt-Date: Fri, 01 Mar 2019 06:24:14 +0000
ASKER
so if a user on the comcast.net platform, emails
1. old server
2. new server
it fails ?
Yes, exactly -- the interesting part is that if all of the users in the email are on the old or the new (but not both) the email goes through. Very strange. There is only one MX record because there is only on IP address.
how is email being delivered to your servers ?
one single SMTP server for the domain (site)
one single SMTP server for the domain (site)
ASKER
Yes. Mail is routed to the Barracuda email security appliance and then to the exchange 2010 server. If the mailbox is not on that server it forwards to the old sbs server.
I know this is working fine both in and out because I can send to both old and new together, from my gmail account and everyone gets it.
I know this is working fine both in and out because I can send to both old and new together, from my gmail account and everyone gets it.
Okay, I understand that the Barracuda email security appliance is the End Point in your organisation.
So SBS2003 and 2010 in the same Exchange Organisation ?
Therefore it does seem the fault lies in the COMCAST.NET.
Is it one of their mail servers delivering mail (e.g. smart hosts) or client on their infrastructure using DNS lookup.
So SBS2003 and 2010 in the same Exchange Organisation ?
Therefore it does seem the fault lies in the COMCAST.NET.
Is it one of their mail servers delivering mail (e.g. smart hosts) or client on their infrastructure using DNS lookup.
ASKER
Yes, Andrew and there are no entries in the Barracuda logs for these user1+user2 emails. But if I send them individually, sure enough, they show up. This has been going on for about a week and a half now and Comcast rarely answers their phone.
if you want to send me your email addresses and domains privately, we can run some bounce tests here, with tool sets we use.
ASKER
Done. Thanks.
ASKER
Andrew, did you find anything?
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1. old server
2. new server
it fails ?