Office 365 Migration Issues: On premise account cant communicate with accounts created in 365!!

Eromonsele Eboiyehi
Eromonsele Eboiyehi used Ask the Experts™
on
I just successfully setup the Hybrid migration for office 365  on my exchange 2010 server on premise. i migrated two mail boxes to office 365, that was successful as well. i can route messages back and forth between the migrated accounts and the on-prem accounts. then i created a new account on office 365, when i try to communicate with that account from my on-prem emails i get a bounce-back error saying the account doesn't exist.  but i receive emails from  from the account. what could be the problem.

N.B: as per dns:
1. my mx records are pointing to the on prem server.
2: I have autodiscover pointing to my onprem as well.
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Commented:
when  you have the Hybrid setup in place, and Migrate particular users mailbox to the cloud, exchange will push an update to those settings to that user.
 
The user will get a notification to the effect 'the administrator has updated your settings and you must restart outlook'.  

Once the user restarts, their RPC/HTTP settings will have changed to point to Office365.

all the best
Jose Gabriel Ortega CastroTop Rated Freelancer on MS Technologies
Awarded 2018
Distinguished Expert 2018

Commented:
What you need to check also are the connectors from onprem to O365.

From Exchange:
Create the send connector to O365
https://docs.microsoft.com/en-us/exchange/mail-flow-best-practices/use-connectors-to-configure-mail-flow/set-up-connectors-to-route-mail

From O365,
After finishing the Hybrid it usually gives an error with the certificate configuration on the client, I always modify that setting to match the Public IP of the on-prem server instead of the certificate, for some reason I get 100% error on that default connector once the hybrid configuration is done.

Jose Ortega
MichelangeloSystem Administrator / Postmaster
Commented:
You have created a cloud only account which had no match on prem. Remember, authority is a n prem AD. You must provision mailboxes by creating them on prem and moving them afterwards or by enable-remotemailbox (then you need to update the exchangeguid on prem)
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Saif ShaikhServer engineer

Commented:
After completing the hybrid setup you need to do 2 additional things,

1. allow office 365 IP's on firewall so that onpremise users receive email from o365.
2. Set spf record in public Dns for office 365 which includes onpremise exchange server public IP.

Since you created a mailbox in cloud there is nothing too do with remote mailbox attribute. Mail flow will flow from office 365 and will check mx if it's pointed to onpremise if will be delivered to onpremise mailbox.

Check the message trace in office 365 and check we're the future is.
Eromonsele EboiyehiNetwork Support Analyst

Author

Commented:
On Prem Users receive from office 365 already. the issue is On Prem cant send to office 365
Saif ShaikhServer engineer

Commented:
Please provide details NDR or message header. Also do you have smarthost in between when sending from onpremise to O365.
MichelangeloSystem Administrator / Postmaster
Commented:
That is because onprem you’re missing the info about sally. Adconnect does not replicate back users from cloud to onprem.
Commented:
@michelangelo is spot on- This is case of the missing remoteMailbox ---
enable-remotemailbox -identity ONPREM-SAMACCOUNT -RemoteRoutingAddress ALIAS@VANITYDOMAIN.ONMICROSOFT.COM
Saif ShaikhServer engineer

Commented:
Hello Jacob,

As per the query he has created a new mailbox in O356 (In cloud). The mailbox was not created as a new mailbox using EMC in onpremise. So as far as I know when you create a new mailbox using EMC when in hybrid setup it does not stamp the onmicrosoft address or target address to the new user which was created in onpremise. Hence when sending email to this new user we receive an NDR.

This command needs to be run at that time: enable-remotemailbox -identity ONPREM-SAMACCOUNT -RemoteRoutingAddress ALIAS@VANITYDOMAIN.ONMICROSOFT.COM

But when a mailbox is created out of hybrid I mean the new user was not AD synced here it was created in cloud so enable-remotemailbox is something which is!!!! may be I might be wrong here...
Eromonsele EboiyehiNetwork Support Analyst

Author

Commented:
Do i run this command "enable-remotemailbox -identity ONPREM-SAMACCOUNT -RemoteRoutingAddress ALIAS@VANITYDOMAIN.ONMICROSOFT.COM" on my on-prem EMC shell?
System Administrator / Postmaster
Commented:
Yep. Do not use an address you have already used for the cloud user. If you have to, delete cloud user and check for sync errors before provisioning the new one
MichelangeloSystem Administrator / Postmaster

Commented:
Also see here for a correction of this issue
https://msb365.abstergo.ch/?p=866
Eromonsele EboiyehiNetwork Support Analyst

Author

Commented:
it worked. Thanks guys. All i needed to do was to provision the user  on AD and enabled the remote mailbox. that did the magic.  
This was the command i ran below;
Enable-RemoteMailbox "Kim Akers" -RemoteRoutingAddress "kima@contoso.mail.onmicrosoft.com
and boom. it worked

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