Hello,

I have a problem in Exchange online. We hired an external company to perform our Microsoft 365 migration. We had our Exchange 2007 data (We have a SBS 2008 server) migrated to Exchange online.

For one user (user X) that was created online, there was a mistype in his name usre X (Instead of user X). Then the external company imported all the mail of that user. I saw the wrong username and we changed the username from usre X to the correct user X.

But: all the mails previous to the moment we changed the username, are still shown with usre X as sender :-(

This is the case in both the mails shown in the browser as in the local Outlook 2010 clints of all our users that imported the Exchange online E-mails.

How can we resolve this issue?

Many thanks in advance.

Greetings,

Peter

• Edited by Peter tLH 13 hours 4 minutes ago
• Changed type Peter tLH 13 hours 2 minutes ago Chose wrong type

Hi,

In this forum we mainly provide suggestions about Office client products. As this problem has occurred since the migration from Exchange 2007 to Exchange Online, I may not guarantee the root cause.

Anyway, here is my opinion:

I've seen some similar issues, that emails sent from the "old name" won't change even the account has a new name, it is possibly by design. Both Exchange and Outlook may treat these received emails from the "old name" as received from another account, that is, Exchange and Outlook may consider usre X and user X as two different accounts, so the new account name won't reflect to the old emails.

As mentioned this is not the dedicated forum for Exchange Online, to confirm this I suggest you post the question in the more appropriate forum:

https://community.office365.com/en-us/f/

The reason why we recommend posting appropriately is you will get the most qualified pool of respondents, and other partners who read the forums regularly can either share their knowledge or learn from your interaction with us. Thank you for your understanding.

Regards,

Melon Chen
TechNet Community Su

Hi Peter,

This is how it is. Consider this scenario, If you have old emails from John@contoso.com. Now John leaves the organization and the mailbox is deleted by IT.

Two things would happen:

1. If addresses were updated like this, your old emails would now be without any sender(Blank), which is undesirable.

2.If we had to replicate any changes to the mailbox account, name, email id etc. to all the old emails across all the mailboxes, it would be chaos.

Hence considering these points, its best that old emails have these information hard-coded to the header of the Item and are not been affected by changes to the original sender.

It does pose some issues with Cached Contacts and NDRs, but its best doing it this way.

This behaviour is similar to what happens when you edit someone's email id. How Exchange is going to know, which email items to update and which to not. What if some new John@contoso.com comes, who is not the original John who left the org.

References:

View e-mail message headers:

E-mail message headers provide a list of technical details about the message, such as who sent it, the software used to compose it, and the e-mail servers that it passed through on its way to the recipient.

https://support.office.com/en-ca/article/View-e-mail-message-headers-cd039382-dc6e-4264-ac74-c048563d21

Hello Satyajit,

Yes I understand what you are saying and it perfectly makes sense that this is the way email works. But still I am presented with a challenge:

How can I best solve this situation? The mistyped name was from on of our managers and now his name is mistyped in all previous mails that are stored online and that are synced to the local profiles of all our users.

Wat steps should I take to get a situation where these emails are present with the correct name of our managers?

Greetings Peter.