Prevent users from adding third party email accounts to Outlook, but with exceptions

[Kiril]

I want to prevent users from adding private email accounts in Outlook Desktop on their Windows Laptops. There must be an exception however, because some user have Microsoft 365 accounts in another tenant which belongs to our organization.

So, is there a possibility to generally prevent the addition of email accounts to Outlook, but provide a domain white list for which the addition of the Outlook account is still possible?

[#2]

Hi @Kiril,

you can try to use

Group Policy Object (GPO):
Apply a Group Policy Object to prevent users from adding email accounts to Outlook. Depending on the Outlook version:

• For Outlook 2016, 2019, and 365, set HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\Options DWORD values DisablePOP3 and DisableIMAP to 1.
• Use the GPO setting Prevent users from adding e-mail account types.

Disable the users from adding email accounts to Outlook. - Microsoft Community

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Leon Pavesic
(LinkedIn)

[#3]

Thank you, we already tried that, but this disables all accounts from being added to Outlook. We are looking to keep accounts from a specific domain.