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Dear Expertise,
In my on-premises Exchange environment, some users are unable to log into Outlook mobile devices. However, these same users can log in using other mobile email apps such as Gmail or the default email app through the email address.
Here's the scenario:
A user's email address/SMTP is "@abc.com" and their logon address/UPN is "@xyz.org". The user is unable to log in to mobile Outlook using the email address/SMTP "@abc.com", but they can successfully log in using only their logon address/UPN "@xyz.org" if they select it as the email address in mobile outlook.
I have also tested using Microsoft Connectivity Analyzer, and it passed. However, users are still unable to log in to mobile Outlook using the "******@abc.com" address, while other mail apps can log in successfully. I have checked all URLs, and they are configured perfectly.
If I am not mistake, user should be to login through both email address and UPN.
How can I solve it.
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Hi @Dipto (Dipto Adhikary) Thanks for reaching out.
If I am not mistaken your user email address and UPN is different in your Exchange Environment. Can you please share your Exchange Server Version.
As in few of exchange version this is not supported as UPN is the primary identifier for an authentication purpose.
If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
@Hriday Saha
Users is unable to log in to mobile Outlook using the email address/SMTP "@abc.com", but they can successfully log in using only their logon address/UPN "@xyz.org"
Exchange server 2016 CU23 & SU3 have in our environment.
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Hi @Dipto Adhikary ,
According to your description, as Hriday Saha said, your problem is caused by the mismatch between the user's email address/SMTP and login address/UPN. This problem has occurred to many users recently. According to my experience, you only need to change the user's email address/SMTP to match UPN.
Is there any update on this thread? If the issue has been resolved, please mark the helpful replies as answers, this will make answer searching in the forum easier and be beneficial to other community members as well. Thanks for your understanding.
@Anonymous For which version of Exchange Server is this problem applicable? In my environment, I have Exchange Server 2016 CU23 & SU3. If you have any reference for it, please share with me. I am waiting for your feedback.
Hello @Dipto Adhikary,
There is currently no official document for your reference. Recently, many internal users have had similar problems to yours, and they were all solved through this method. It is recommended that you try it to see if the problem can be solved.
