id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
31574	EmailMessage.cc/to/bcc cannot mix tuples and lists as arguments.	Joe Huang	nobody	"`EmailMessage` has fields `to`, `cc`, and `bcc` that can be either tuples or lists. However, mixing tuples and lists errors at this method:

{{{
def recipients(self):
    return [email for email in (self.to + self.cc + self.bcc) if email]
}}}

Lists and tuples can't be added together."	Bug	closed	Core (Mail)	dev	Normal	worksforme			Unreviewed	0	0	0	0	1	0