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
17444	Allow different MAIL TO and `To` headers	Ethan Jucovy	nobody	"Currently the `EmailMessage.message` method sets the email's `To:` header to match the `to` argument to the message object's constructor.

It can be useful to set a `To:` header that is different from the actual recipients of the message.  For example, when implementing a mailing list, the `To:` header can be set to the mailing list's address itself.

Currently, however, if you pass a custom `To` header in the constructor's `headers` argument, the resulting message contains two `To` headers.

I've provided a patch with tests that will instead look for a custom `To` header in `extra_headers` when constructing the mail message, defaulting to the present behavior if no custom `To` header was provided.  This is analogous to the approach taken for the `From` header, which was implemented in #9214."	Bug	closed	Core (Mail)	dev	Normal	fixed			Ready for checkin	1	0	0	0	0	0