+@cindex X-Message-SMTP-Method
+\e$B$b$7J#?t$N\e(B @acronym{SMTP} \e$B@_Dj$r;H$&$3$H$,$G$-$F!"$"$k%a%C%;!<%8$O0l$D\e(B
+\e$B$N%a!<%k%5!<%P!<$r7PM3$7!"B>$N%a%C%;!<%8$OJL$N$b$N$rDL$7$F=P$7$?$$>l9g$O!"\e(B
+@samp{X-Message-SMTP-Method} \e$B%X%C%@!<$r;H$&$3$H$,$G$-$^$9!#0J2<$O%5%]!<\e(B
+\e$B%H$5$l$F$$$kCM$G$9\e(B:
+
+@table @samp
+@item smtpmail
+
+@example
+X-Message-SMTP-Method: smtp smtp.fsf.org 587
+@end example
+
+\e$B$3$l$O\e(B @samp{smtp.fsf.org} \e$B$N%]!<%H\e(B 587 \e$B$r7PM3$7$F%a%C%;!<%8$rAw$j$^$9!#\e(B
+
+@example
+X-Message-SMTP-Method: smtp smtp.fsf.org 587 other-user
+@end example
+
+\e$B$3$l$O>e$N$b$N$HF1$8$G$9$,!"G'>Z$r9T$J$&$H$-$K\e(B @samp{other-user} \e$B$r%f!<\e(B
+\e$B%6!<L>$H$7$F;H$$$^$9!#$3$l$O!"F1$8%5!<%P!<$KJ#?t$N\e(B @acronym{SMTP} \e$B%"%+%&\e(B
+\e$B%s%H$r;}$C$F$$$k>l9g$KLrN)$A$^$9!#\e(B
+
+@item sendmail
+
+@example
+X-Message-SMTP-Method: sendmail
+@end example
+
+\e$B$3$l$O%m!<%+%k$K%$%s%9%H!<%k$5$l$F$$$k\e(B sendmail \e$B$d\e(B exim \e$B$J$I$r7PM3$7$F%a%C\e(B
+\e$B%;!<%8$rAw$j$^$9!#\e(B
+@end table
+