Solved

SMTP Shared Namespace and Distribution Groups

Posted on 2015-02-06
7
129 Views
Last Modified: 2015-05-12
We have the short term need to setup an SMTP Shared Namespace on a single email domain.
At the moment the primary MX is setup to send mail to O365 first.  Then O365 has an Internal Relay setup to point to an Exchange 2007 for any addresses not local to O365.  Obviously the Exchange 2007 box has the same internal relay setup to cover internal mails for users based back on O365.
Mails addressed to specific people works fine between servers as does incoming mail from external users to the new domain.

My question is how to cover a distribution group that is split across sites.
Rather than adding 100 odd mail contacts at each site, we figured the best way would be, for each cross site list, to have a group at each site with two SMTP addresses, one for shared domain.com and one for nonshareddomain.com.
I then figured if we setup mail contacts at the opposite site to have a contact for group@nonshareddomain.com it would cover it i.e

everyone@shareddomain.com contains a list of local users to the local mail server.
On O365, that list also includes a contact for everyonerelay@nonshareddomain.com

That way, if an O365 user sends a message to everyone@, that message gets relayed to the other site, which in turn distributes it to all the other sites local users.

However, am I right in thinking that if we have a smiler relay contact setup in everyone@shareddomain in the other site, we will potentially create an infinite loop, as it will be trying to send back to everyonerelay@nonsharedomain.com at the first site.

Hope this ramble makes sense.
0
Comment
Question by:Neil Potter
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 4
  • 2
7 Comments
 
LVL 16

Expert Comment

by:Ivan
ID: 40594265
Hi,

regarding that internal relay setup..if you don't have server that is authorative for a domain, and some one send an email to a person that does not exist..what is going to happened to that email?
Endless loop between Office 365 and Exchange 2007..

PS: I just read last part of you message...yeah, infinitive loop.
0
 

Author Comment

by:Neil Potter
ID: 40594273
Yeah thats what i'm thinking.  Is there any way around it?

With it being O365 Exchange at one end and 2007 at the other, in theory they have the default 30 hop limit anyway, but will this just bounce back and forth 30 times then stop, or will it actually deliver up to 30 emails to the same people?
0
 
LVL 16

Accepted Solution

by:
Ivan earned 500 total points
ID: 40594276
Correct setup, if you don't have hybrid deployment would be to setup Exchange 2007 as authorative, and make it host all mailboxes.
Then you configure forwarding, so that when email for users on Office 365 is sent from on-premiss users, it is forwarded to their username@domain.onmicrosoft.com email.

Email does get received to Exchange 2007 mailbox, so you have to make sure mailbox is not full,
0
Best Practices: Disaster Recovery Testing

Besides backup, any IT division should have a disaster recovery plan. You will find a few tips below relating to the development of such a plan and to what issues one should pay special attention in the course of backup planning.

 
LVL 16

Expert Comment

by:Ivan
ID: 40594281
When on-premiss user want to send email to Office 365 user:

on-premiss user --> Exchange 2007 (user@domain.com) --> server forward rule to user@domain.onmicrosoft.com
0
 
LVL 16

Expert Comment

by:Ivan
ID: 40594283
It would bounce, would not get delivered many times.
0
 
LVL 31

Expert Comment

by:Gareth Gudger
ID: 40596252
Can you explain the short term need a little more? Just curious what the business need was behind splitting your namespace.

What about taking on premise to Exchange 2013 and configuring Hybrid?
0
 

Author Comment

by:Neil Potter
ID: 40596587
We are going through a company merger.  My company has O365 with DirSync.  The other company has on premise Exchange 2007.
We have used shared namespace for the new email domain.
So mail comes into our O365 first.  Any "unknown" users get passed on to their On Premise server to be handled or bounced.
On their server, if one of their users sends a message to the new domain, if unknown it bounces it to O365.

We've had to take this approach as we have some data compliance issues preventing us from linking the sites and AD servers.  The long term plan is to link the sites, migrate the old AD's into a new single forest, and Stage Migrate their mailboxes up to O365.
0

Featured Post

Free Tool: Path Explorer

An intuitive utility to help find the CSS path to UI elements on a webpage. These paths are used frequently in a variety of front-end development and QA automation tasks.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
Track who logged into an Office 365 Exchange account 2 47
eFolder Discontinued Product Keys No Longer Available 2 25
exchange 2007 , mailbox 3 34
query all mailbox rules 5 34
This article lists the top 5 free OST to PST Converter Tools. These tools save a lot of time for users when they want to convert OST to PST after their exchange server is no longer available or some other critical issue with exchange server or impor…
How to resolve IMCEAEX NDRs in Exchange or Exchange Online related to invalid X500 addresses.
In this video we show how to create an Address List in Exchange 2013. We show this process by using the Exchange Admin Center. Log into Exchange Admin Center.: First we need to log into the Exchange Admin Center. Navigate to the Organization >> Ad…
In this Micro Video tutorial you will learn the basics about Database Availability Groups and How to configure one using a live Exchange Server Environment. The video tutorial explains the basics of the Exchange server Database Availability grou…

697 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question