Small email sending code improvements

[paolobarbolini]

Changes building Address by going through the FromStr implementation. Also removes the manual MultiPart build implementation, which must have been a workaround for a bug in a previous version.

Depends on #2531

[BlackDex]

Thanks @paolobarbolini , looks nice.
Regarding the Punycode, i have no clue actually, i tested it without the conversion, and it seems to work just fine.
@dani-garcia do you remember why you added that maybe?

[dani-garcia]

We changed it to use punycode because of a user having trouble using it with an internationalized domain: #829.

Not sure if that issue is applicable still.

[BlackDex]

Looking at the changes done on the lettre side, i think this should be fixed now right @paolobarbolini ?

[paolobarbolini]

Looking at the changes done on the lettre side, i think this should be fixed now right @paolobarbolini ?

I'll have to test it somehow because I don't think we ever got any issues reported about IDNs, so unless we happened to fix it in the middle of doing other changes we're still handling them wrong.

[BlackDex]

@paolobarbolini Well you changed the email verifying now right? So that might have solved it right now?
I did some testing with several unicode domains, and it looks like not generating an issue.

[paolobarbolini]

@paolobarbolini Well you changed the email verifying now right? So that might have solved it right now? I did some testing with several unicode domains, and it looks like not generating an issue.

Ah right. The error is in the fact that verification was broken, not that we didn't encode the email properly 😅

[paolobarbolini]

Changed it. I didn't realize when the issue came up lettre 0.10.0-alpha.1 hadn't even been released yet, so it was still using the ancient email builder. This 0.10 release has been in the making for a long time 😄