Internationalized email (SMTPUTF8) support

[rimas-kudelis]

E-mail addresses can now be properly internationalized. The relevant RFCs, while not fully supported by all systems, have been around for a while, and internationalized email appears to be supported by Exim as well.

However, when I set up an email account with non-ASCII characters in both account name and domain name, I couldn't quite get it to work reliably: I just couldn't receive emails reliably regardless of whether I registered the domain with Exim in punycode or in UTF-8.

This issue is to track internationalized the support for internationalized email. I suppose we'll have to consult with Exim on which way the domains should be stored in the database and how to make that work.

[Zetanova]

I had problems with emojis in the mail subject and the subject blacklist filter.
The solution was to change all db-columns from utf8mb3 to utf8mb4

[rimas-kudelis]

Yes, this was addressed in 94842ac.
This issue is about raw UTF-8 characters in mail headers and email addresses.

[Udera]

However, when I set up an email account with non-ASCII characters in both account name and domain name

Did you try sending a mail to non-ascii addresses?

[rimas-kudelis]

However, when I set up an email account with non-ASCII characters in both account name and domain name

Did you try sending a mail to non-ascii addresses?

Isn't that what I said in the sentence that folloed? 😃 Yes, I did, but I couldn't figure out what the correct way to configure non-ascii domains and non-ascii mailboxes is in Exim.