This PR is stale because it has been open for 30 days with no activity.

What exactly is missing for this PR to get applied? It would be great because this bug is affecting my productive system and I have to monkey-patch the email library by myself.

I am getting this bug in a production environment.
It seems emails from the sender azuredevops@microsoft.com have a message id starting with <[

How is this PR not yet reviewed after- all this time? How can we notify the right people to review this?

@python/email-team

Same here, got this on my production environment, preventing me to upgrade from Python 3.7.3 (bug not present) to a more recent version (bug confirmed in 3.8, 3.9, 3.10, 3.11).

Easy to trigger:

import email.parser
import email.policy
faulty_header = "Message-ID: <[9f83415a58f84675bac8ab3e6047a157-JFBVALKQOJXWILKCJQZFA7CJIFGVGU2QKJ6FGU2QKJCW2YLJNR6EK6DPKNWXI4A=@example.com]>"
message = email.parser.BytesParser(policy=email.policy.default).parsebytes(faulty_header.encode("utf-8"))
message.as_bytes()

Is there an ETA for this please?

I have a competing PR which does not simply silently ignore the problem, but instead raises a defect. My proposed implementation returns a partial message-id which is perhaps less than ideal.

#108133

Thank you for your contribution, @ZackerySpytz, but I think that it is not a correct solution. Invalid Message-ID should not be silently truncated. The parsing code should raise HeaderParseError, this will allow to preserve its literal value. See #117934.