CODEWITHSUNDEEP
emailemail-validationemail-addressrfc5322
Jan Köhler
Jan Köhler

Reputation: 6030

Are international characters (e.g. umlaut characters) valid in the local part of email addresses?

Are german umlauts (ä, ö, ü) and the sz-character (ß) valid in the local part of an email-address?

For example take this email-address: björn.nuß[email protected]

RFC 5322 quite clearly says, that umlauts (and other international characters) aren't allowed. If I take a look at chapter 3.4.1, there's the following regarding the local part: local-part = dot-atom / quoted-string / obs-local-part So what means dot-atom? It's described in chapter 3.2.3: Well, long story short: Printable US-ASCII characters not including specials

So in the whole RFC 5322 I can't see anything regarding international characters. Or is RFC 5322 already obsolete? (RFC 822 -> RFC 2822 -> RFC 5322)

Update: The important point for me is: What's the current standard? International characters allowed or not? RFC 5322 is marked as DRAFT STANDARD. So I think that's the most recent source to rely on, isn't it?

Efran mentioned, that RFC 5336 allows international characters. But RFC 5336 is marked as EXPERIMENTAL, so that's not interesting for me.

Upvotes: 24

Views: 34255

Answers (4)

muratgozel
muratgozel

Reputation: 2589

No, local-part can either be dot-atom or quoted-string. They are both can't go beyond US printable characters. You can rely on the RFC5322 (and related extension specs) because they are backwards compatible and practiced widely. You might have been tried to look at RFC2047 which is an extension for RFC5322 and describes encoding methods for non-us-ascii text in emails but as stated in section 5:

An 'encoded-word' MUST NOT appear in any portion of an 'addr-spec'.

Email clients will reject emails that contain invalid addresses such as björn.nuß[email protected] even if your email composer/client would allow it.

Upvotes: 1

Efran Cobisi
Efran Cobisi

Reputation: 6454

Yes, they are valid characters as long as the mail exchanger responsible for the email address supports the UTF8SMTP extension, discussed in RFC 5336. Beware that just a small portion of the mail exchangers out there supports internationalized email addresses.

Our email verification service, for example, allows UTF8 characters in the local part of an email address but will mark it as undeliverable if its related mail exchanger(s) does not support the aforementioned extension.

Upvotes: 17

grin
grin

Reputation: 327

https://www.rfc-editor.org/rfc/rfc5322#section-3.4.1 is your latest standards track reference. Generally it is not advisable to use characters which require quoting due to the outrageously high amount of standards unconformant MTAs out there. Such email are bound to get lost in the long run.

As a friendly advice this table is pretty useful too (from Jochen Topf, titled "Characters in the local part of an email address"): https://www.jochentopf.com/email/chars.html

Upvotes: 4

Geordie Korper
Geordie Korper

Reputation: 31

It looks like rfc6531 replaces 5336 and it is "PROPOSED STANDARD" https://www.rfc-editor.org/rfc/rfc6531

Upvotes: 2

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