New Outlook cannot add IMAP account – “Changing the ImapRemoteServerInfo is not allowed”

Question

New Outlook cannot add IMAP account – “Changing the ImapRemoteServerInfo is not allowed”

Sercan Egilmezkol 0

We have an IMAP email account: [Moderator note: Personally Identifiable Information removed]@avciss.com.

The account was previously working correctly in New Outlook with the following settings:

IMAP server: avciss.com

IMAP port: 993

IMAP encryption: SSL/TLS

SMTP server: avciss.com

SMTP port: 587

SMTP encryption: None

The mail server configuration was subsequently changed to the following:

IMAP server: mail.avciss.com

IMAP port: 993

IMAP encryption: SSL/TLS

--
SMTP server: mail.avciss.com

SMTP port: 465

SMTP encryption: SSL/TLS

The new settings work correctly in webmail and Classic Outlook.

However, we cannot add this account to New Outlook anymore. We have tried on multiple different PCs and get the same result.

Another IMAP account on the same mail server ([Moderator note: Personally Identifiable Information removed]@avciss.com) can be added to New Outlook successfully using the new server settings. But please keep in mind, this account ([Moderator note: Personally Identifiable Information removed]@avciss.com) was not using New Outlook before. It was used with Outlook Classic.

We investigated the New Outlook request using DevTools. When trying to add the account with the current server settings, Microsoft returns the following response:

"idpStatusCode": "BadRequest",

"error": "BadRequest",

"errorDescription": "Changing the ImapRemoteServerInfo is not allowed. Attempted to changed it from 'avciss.com' to 'mail.avciss.com'"

We also tested the old server name (avciss.com). In that case, authentication fails with:

"idpStatusCode": "Unauthorized",

"error": "InvalidCredentials",

"errorDescription": "Unable to authenticate with credentials provided"

The credentials are valid because the same account works correctly in webmail and Classic Outlook using the current settings.

It appears that New Outlook / Microsoft's Cloud Account service still has an old IMAP server reference (avciss.com) associated with this email account and does not allow it to be changed to the current server (mail.avciss.com).

Could you please advise how we can reset or remove this old IMAP/Cloud Account reference so that the account can be added to New Outlook using the current IMAP server, mail.avciss.com?

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2 answers

Your answer

Answer 1

Alina Le 4,920 Independent Advisor

Hello Sercan,

If I understand correctly, this specific IMAP account previously worked in New Outlook when the mail server was configured as avciss.com. However, after the server was changed to mail.avciss.com, the account can no longer be added to New Outlook. Meanwhile, the same mailbox continues to work correctly in webmail and Outlook Classic, and another IMAP account hosted on the same server can be added successfully using the new server settings.

"errorDescription": "Changing the ImapRemoteServerInfo is not allowed. Attempted to changed it from 'avciss.com' to 'mail.avciss.com'"

I would suggest some troubleshooting steps for you to see if it helps:

1/ Remove the account completely from New Outlook

Please check whether the mailbox is still listed anywhere in New Outlook.

Open New Outlook.

Select "Settings" in the top-right corner.
Select "Accounts".

Locate the affected mailbox.

Choose "Remove".

If you see the option"Remove from all devices", please select it as well. This option has been suggested in a similar case involving New Outlook retaining previous account configuration information.

This step helps ensure that New Outlook is not reusing previously stored account settings.

*Before you begin:

Please make sure you know the mailbox password before removing the account.
You may be asked to sign in again after the account is removed.

2/ Add the account using "Advanced Setup"

Verify whether New Outlook can create a completely new IMAP profile instead of reusing previously stored server details.

Open New Outlook.
Select "Add Account".
Enter the email address.
If Outlook starts automatic account detection, select"Cancel" when available.
Select "Advanced Setup".
Manually enter:
- IMAP Server: mail.avciss.com
- IMAP Port: 993
- Encryption: SSL/TLS
- SMTP Server: mail.avciss.com
- SMTP Port: 465
- Encryption: SSL/TLS

Reference thread:

I changed Hosting Provider and associated DNS. New Outlook keeps reconfiguring accounts with previous host's servers

I hope I've been able to help in some way. Please keep me posted.

Kind regards,

Sercan Egilmezkol 0 Reputation points

2026-08-31T13:40:47.92+00:00

Hello Alina,

I removed this account without the option you requested. "Remove from all devices."
I chose "Remove from this device."

Now I don't have option to create this account on New Outlook. So, I don't have option to remove also.

Can you please check the situation with this information?

Sincerely, regards,
Alina Le 4,920 Reputation points Independent Advisor

2026-08-31T16:28:07.05+00:00

Hi,

I am still here for you.

I will review this issue again based on the information you provided and update you soon.
Sercan Egilmezkol 0 Reputation points

2026-08-31T17:29:35.23+00:00

Hi,

First of all, thx for your support.

Please keep in mind, the other account ([Moderator note: Personally Identifiable Information removed]@avciss.com) was not using New Outlook before. It was used with Outlook Classic. So, for that account we didn't enter "avciss.com" information to the New Outlook before.

We gave above info just to make you know that our server is working fine with New Outlook for new configuration below:

Imap: mail.avciss.com

993

SSL

Smtp: mail.avciss.com

465

SSL

Sincerely
Alina Le 4,920 Reputation points Independent Advisor

2026-09-01T19:55:53.31+00:00

Hello Sercan,

Thank you for the additional details.

Based on the information currently available, I am unable to determine the exact root cause of the issue.

At this point, the available troubleshooting results are not sufficient to confirm whether the issue is caused by a client-side configuration, a cloud mailbox record, or another service-side dependency. Further investigation would require access to diagnostic data and backend information that is not available through the standard troubleshooting process.

Therefore, I would recommend contacting Microsoft Support Engineering for a deeper investigation. When doing so, please provide the DevTools error message, the previous and current IMAP server names, and the details you have shared in this thread. This will help the support team review the account configuration and related service logs in more detail.

You can sign into the "Microsoft Admin Center to reach out Microsoft Support Engineering.

(Please kindly ask your IT Admin to do it for you)

Kind regards,

Answer 2

Helmut Bezolt 0

@Alina Le Isn't it the same issue as: https://techcommunity.microsoft.com/discussions/OutlookGeneral/new-outlook-changing-the-imapremoteserverinfo-is-not-allowed-after-host-migratio/4533161

From what I have read there is that the server caches the old IMAP configuration and doesn't allow a new one.

I have the same issue on an account.

Alina Le 4,920 Reputation points Independent Advisor

2026-09-07T13:51:23.22+00:00

Hi Helmut,

As I mentioned, this issue requires support from Microsoft Engineering to comprehensively investigate the problem and provide a more accurate answer.

You can refer to my response above, or you can create a separate thread to have the entire issue reviewed specifically for your case.

Even when symptoms look similar, the root cause often differs by environment, account type, add-ins, and recent changes. A dedicated thread helps to avoid cross‑signals and accelerate troubleshooting.

To create your thread: go to Microsoft Q&A, click “Ask a question”, select the product/tag, and paste the above details.