smtplib mixes RFC821 and RFC822 addresses

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2018-09-05.20:41:44.008>
labels = ['type-security', 'library']
title = 'smtplib mixes RFC821 and RFC822 addresses'
updated_at = <Date 2020-03-23.18:01:04.929>
user = 'https://github.com/daurnimator'

bugs.python.org fields:

activity = <Date 2020-03-23.18:01:04.929>
actor = 'Manjusaka'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Library (Lib)']
creation = <Date 2018-09-05.20:41:44.008>
creator = 'daurnimator'
dependencies = []
files = []
hgrepos = []
issue_num = 34591
keywords = []
message_count = 4.0
messages = ['324653', '364200', '364220', '364869']
nosy_count = 3.0
nosy_names = ['daurnimator', 'Manjusaka', 'epicfaace']
pr_nums = []
priority = 'normal'
resolution = None
stage = None
status = 'open'
superseder = None
type = 'security'
url = 'https://bugs.python.org/issue34591'
versions = []