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RaulChiarella avatar image
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RaulChiarella asked joyceshen-MSFT commented

Office 365 sync problem after migration from Exchange. Help?

Hello!

I came here because i do not know what to do anymore.
Here's what happened:

We had POP mail, and some Exchange Mail here in my company.
All users are using Outlook - It synced with mailex13...exhcange server.

But Exchange and POP mail aren't good enough, so we canceled our contract with the Exchange mail provider and hired Microsoft 365 directly with Microsoft, so now all users can use all resources 365 has to offer!

We did the following proccess for all users on the migration proccess:

  1. Created a new profile on Outlook, called "User 365"

  2. Logged - in with Active Directory synced user, to log-in in 365.

  3. OK! Done.

Now users started using Outlook just fine, with 365 account - Using their respective Active Directory user.

But then, a HUGE problem started happening on ALL the computers that had exchange accounts!
Computers that had POP accounts didnt show this problem...

The problem: Out of NOWHERE Outlook simply started CHANGING the Office 365 URL that appears on the account when clicking "File" tab on Outlook and the OLD URL from a totally different server!

Instead of syncing with the default Outlook.office365.com URL it just replaced with the old one from the other server, like ?? Wtf. I have no idea what to do!

The only way to fix this was to delete the user folder, and login again. But after some time Outlook simply changed AGAIN to the old Exchange URL...

So, here are the facts: Using Office 365 web the problem doenst happen.
On a formatted computer the problem doesnt happen.
Problem didnt occur on POP accounts.

My guess is that for some reason Windows/Outlook profile saves Server information somewhere that i am not seeing.

Registry?
System?

Please, can someone point me in the right direction so i can simply delete ALL previous informations of the old server?

Where does Outlook stores information about Mail Server, so i can manually delete and Outlook will then finally stops changing to old urls that are not in use anymore.

I am very sorry if my explanation here got a little confused, since i am not a native speaker.
If you guys have any questions please let me know...

office-exchange-server-administrationoffice-outlook-itprooffice-exchange-online-itpro
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Hi @RaulChiarella

Is your environment a hybrid environment, and do you want to decomission your on-prem Exchange server?
I would like to confirm what's the configuration of your MX record, does it point to your o365 or still on-prem?

Could you also please share any screenshot about your outlook profile configuration? Note to clear your personal information.

And this related link for your reference as well: Transport routing in Exchange hybrid deployments


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Hi @RaulChiarella

Is there any further information about your issue here? You could share them here for further troubleshooting

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1 Answer

RaulChiarella avatar image
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RaulChiarella answered joyceshen-MSFT commented

Hello!

Yes, it is hybrid. We have local servers, cloud servers and also third party servers and services.
Previously our Exchange Email was a third party server - Only thing we did to make Outlook work was:
1. Create Outlook Profile
2. Login

Thats it. Then Outlook would automatically configure the Exhcange Server (When i clicked on File > Account it showed the Exchange MailEx13 ... server.)

Then we migrated to Office 365.
The process was very simple:
1. Create a new profile.
2. Login with new email using Office 365 credentials

But the problem is that computers that had Exchange Profile configured, on the new profile created sometimes would just stop working, and when i checked the Account to see if the server was Office 365 it changed to the old Exchange one...

This DOES NOT happens on computers that DIDNT had the older account from the other Exchange Server configured...
This leads me to believe that the old exchange account information is stored directly on the System, maybe in registry?

If there was a way i could delete those info so Outlook can stop switching to the old Exchange Server link...

Regarding MX/DNS config: It's all good. It is poiting to the new 365 Server.
Everything is configured accordingly.

As a result the problem never happens on computers that didnt had information about the previous Exchange Server.

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Hi,

If you have all the mailboxes moved to the cloud, make sure you have correctly performed the below steps for your autodiscover

First, point the autodiscover URL to Exchange Online. After that, null the internal autodiscover URL on the Exchange on-premises server. As of last, remove the internal DNS autodiscover entries.

Details can be seen here: Autodiscover URL in Exchange hybrid
Please Note: Since the web site is not hosted by Microsoft, the link may change without notice. Microsoft does not guarantee the accuracy of this information.


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