emacs.d/mail.org: Configuration for personal SMTP server

Added this a while back; forgot to commit.

emacs.d/mail.org

@@ -96,6 +96,34 @@ can yield a good result, but if I forget to do so, that's a problem.]
                                       (nnimap-authenticator   login))))
 #+END_SRC
 
+While GNU's SMTP server is usually what I use, life is a little more
+complicated.  Personal e-mail that really should only be handled by my own
+servers needs to be sent out using my own SMTP server; otherwise, replies to
+my personal e-mail would have to go out under my GNU address, which isn't
+desirable.
+
+This overlaps a little bit with my Gnus configuration below.
+
+#+BEGIN_SRC emacs-lisp
+  ;; default is mtg@gnu.org, so we need only worry about overrides
+  (setq gnus-posting-styles
+        '(((header "to" ".+@mikegerwitz.com")
+           (address "mike@mikegerwitz.com")
+           (signature-file "~/.signature.mtgcom")
+           ("X-Message-SMTP-Method" "smtp mail.mikegerwitz.com 587"))))
+
+  (defun mail-mikegerwitz.com-p ()
+    )
+#+END_SRC
+
+Gnus supports an internal =X-Message-SMTP-Method= header that will direct
+mail to the desired SMTP server.  [[https://lists.gnu.org/archive/html/help-gnu-emacs/2015-11/msg00031.html][Pretty simple!]]  Any mail at my domain will
+reach me.  Chances are, I want to reply from my main e-mail address
+(especially if I want to GPG-sign my message), but I can change that
+manually if need be.  I often enter unique e-mail addresses for services I
+sign up for to track who sells my data to spammers or might have been
+compromised.
+
 * <<<Gnus>>>
 [[gnus.org][Gnus]] is a popular message reader (that is, newsgroups and the like, in
 addition to E-mail) for Emacs.  It is highly customizable via user