Policy

Disable Internationalized Domain Names (IDN) in Outlook

By default, Outlook supports Internationalized Domain Names (IDN) for SMTP addresses in Outlook if Windows provides the appropriate support for this feature. You can disable IDN support so that Punycode rather than native characters are used for rendering SMTP addresses. You might choose to disable IDN support in Outlook if you do not typically expect non-ASCII characters in SMTP addresses. This setting does not affect the support of IDN in URLs.

Policy
Pack Microsoft Office
Category Microsoft Outlook 2016 / Outlook Options / Mail Format / International Options
Policy ID e523d6e0486d
Internal name L_DisableInternationalizedDomainNamesIDNinOutlook

Registry

Copy registry mappings

HKCU\software\policies\microsoft\office\16.0\outlook\options\general\disableidn (enabled) = 1
HKCU\software\policies\microsoft\office\16.0\outlook\options\general\disableidn (disabled) = 0

Policy notes

By default, Outlook supports Internationalized Domain Names (IDN) for SMTP addresses in Outlook if Windows provides the appropriate support for this feature. You can disable IDN support so that Punycode rather than native characters are used for rendering SMTP addresses. You might choose to disable IDN support in Outlook if you do not typically expect non-ASCII characters in SMTP addresses. This setting does not affect the support of IDN in URLs.

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