Inbound messages never stored their Reply-To header, so Reply and Reply all
in the reader always addressed the From address. Mail from a contact form
(From: no-reply@site, Reply-To: visitor) was answered to the no-reply box.
Store the full Reply-To list in a new messages.reply_to column on delivery
and import, use it as the reply target in getReplyRecipients (falling back
to From when it names only the mailbox's own addresses), surface it on JMAP
Email objects, and let the agent's draft_reply read the column before
falling back to parsing the raw MIME for older rows.
Daniel Quah
07c4d56624