[Mailman-Users] sync_members - doesnt sync E-mail addresses with german umlauts characters (in the domain)

[Richard Damon]

On 8/6/17 2:34 PM, Dlugasny via Mailman-Users wrote:
> Hi,
> sync_members command is not able to sync E-mail addresses with german Umlauts.
>
> [ä, ö,](https://learn-german-easily.com/german-umlauts)
>
> I saw some rules for an valid E-mail domain in .../Mailman/Utils.py
> This kind of characters are allowed in the domain names, but mailman accepting only a-z 0-9. Is it possible to change it ?
> Greetz
> Dlugasny
>
The issue is likely due to the fact that the base protocol document for 
SMTP only allows for 'ASCII' characters in email addresses (and to a 
large extent anywhere in the headers of an email message). There are 
extensions with varying degrees of acceptance that extend this character 
set. (Note, I don't think SMTP needs to be 8 bit clean even for the 
message body, which is why we still have things like BASE64 and 
Quote-Printed encoding for messages).

A second part of the question is to what level does Python email 
libraries support these extensions and how easy is it to figure out how 
the local email system will handle messages that attempt to use them.

-- 
Richard Damon