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our IIS6 is running a smtp service.

This smpt throws the following exception if an email shall be send to an domain with an umlaut.

Exaple: mymail at mydomä etc.

Doesn't the IIS support such email addresses? What can I do about this?

Thank you! Regards, Uwe

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I believe SMTP (as opposed to the DNS system) supports ONLY ASCII, hence the various encodings and MIME-types. It's a limitation of the protocol - I'm not sure of the workaround. – nray Oct 19 '09 at 10:35
up vote 1 down vote accepted

Email addresses need to be ASCII so really you need a domain for email without an umlaut.

There are plans to internationalize this in line with domain names, however this is not standardised yet and will continue to cause problems for some time as people update.

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thanks for that answer. But there are some users using emailadresses with non-ascii domains. how can I handle them? Is there a way to auto convert the domainname to the punycode equivalent? – Uwe Oct 19 '09 at 11:43
you need to do that in your app, so it may be worth asking as another question on stack overflow – JamesRyan Oct 19 '09 at 12:38

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