# Internationalization Internationalization Domain Names (IDN) Mailgun's Messages API supports sending to addresses that use internationalized domain names in the `to` and `from` fields. When necessary, Mailgun will automatically convert the domains to the ADCII equivalent using [Punycode](https://en.wikipedia.org/wiki/Punycode). Note: Currently, sending domains cannot be created using non-ASCII characters. Internationalized Email Addresses (SMTPUTF8) Mailgun supports internationalized email addresses though the use of the SMTPYTF8 extension. An Internationalized email address will contain a non-ASCII character in the local-part portion of the email address and may also use an internationalized domain name. Mailgun supports internationalized email addresses in the following portions of our product: - Outgoing Messages (HTTP API) - Email Verification - Suppressions Lists Note: Match\recipient and forward action are supported for domains using international characters / punycode. However, sending to a punycode domain is not supported. To send messages to an internationalized email address, the receiving mailbox provider must support the SMTPUTF8 extension