Kyle Jones wrote in message: http://www.xemacs.org/list-archives/xemacs-beta/9901/msg00453.html Sounds good in principle. However, in single-stepping through sendmail-send-it using edebug, I see that the 5th arg to call-process-region is *not* 0 but nil. "errbuf" (arg 5) is set to nil if mail-interactive is not set. It should be set to 0 instead. Setting it to zero causes a problem with the code that checks the exit value of the sendmail process, since if the process is executed without waiting, exit-value is nil. I think this problem was introduced in Gregory's change of 1998-10-31 Here's a patch that deals with both problems: ChangeLog for mail-lib: 1999-01-20 Charles G Waldman <cgw(a)pgt.com&gt; * sendmail.el (sendmail-send-it): Execute sendmail in background if mail-interactive is nil, and don't try to check error exit. Index: libs/mail-lib/sendmail.el =================================================================== RCS file: /usr/CVSroot/XEmacs/xemacs-packages/libs/mail-lib/sendmail.el,v retrieving revision 1.3 diff -u -r1.3 sendmail.el --- sendmail.el 1998/12/10 14:37:55 1.3 +++ sendmail.el 1999/01/21 05:59:09 ＠＠ -579,7 +579,7 ＠＠ (require 'mail-utils) (let ((errbuf (if mail-interactive (generate-new-buffer " sendmail errors") - nil)) + 0)) (tembuf (generate-new-buffer " sendmail temp")) (case-fold-search nil) resend-to-addresses ＠＠ -738,7 +738,7 ＠＠ ;; addresses. (or resend-to-addresses '("-t"))))) - (if (not (zerop exit-value)) + (if (not (or (eq errbuf 0) (zerop exit-value))) (error "Sending...failed with exit value %d" exit-value))) (if mail-interactive (save-excursion