diff --git a/mailx-12.5-systemd.patch b/mailx-12.5-systemd.patch
new file mode 100644
index 0000000..2266a3b
--- /dev/null
+++ b/mailx-12.5-systemd.patch
@@ -0,0 +1,29 @@
+To avoid trouble as descbried in boo#1192916
+
+---
+ mailx.1 |   14 ++++++++++++++
+ 1 file changed, 14 insertions(+)
+
+--- mailx.1
++++ mailx.1	2021-11-23 12:33:48.788947209 +0000
+@@ -4793,6 +4793,20 @@ mailaddr(7),
+ sendmail(8)
+ .SH NOTES
+ .PP
++If used in systemd unit files not using
++.B Type=forking
++it is required to set the option
++.I sendwait
++on the command line of
++.BR mailx (1)
++with
++.I \-S sendwait=yes
++as otherwise it might happen that the
++.BR systemd (1)
++service manager will terminate the asynchronously
++started SMTP transfer as described at the option
++.IR smtp.
++.PP
+ Variables in the environment passed to
+ .I mailx
+ cannot be unset.
diff --git a/mailx-12.5.dif b/mailx-12.5.dif
index 37f75e5..29eabc0 100644
--- a/mailx-12.5.dif
+++ b/mailx-12.5.dif
@@ -265,7 +265,7 @@
  This option should be activated for
  .I mailx
  scripts that are invoked on more than one machine,
-@@ -3111,7 +3111,7 @@ in the user's home directory.
+@@ -3113,7 +3113,7 @@ in the user's home directory.
  The name of an optional startup file
  to be read after ~/.mailrc.
  This variable is ignored if it is imported from the environment;
@@ -274,7 +274,7 @@
  to allow bypassing the configuration with e. g. `MAILRC=/dev/null'.
  Use this file for commands
  that are not understood by other mailx implementations.
-@@ -3688,7 +3688,7 @@ Used as directory for temporary files in
+@@ -3696,7 +3696,7 @@ Used as directory for temporary files in
  ~/.mailrc
  File giving initial commands.
  .TP
diff --git a/mailx.changes b/mailx.changes
index 521437f..ab97111 100644
--- a/mailx.changes
+++ b/mailx.changes
@@ -1,3 +1,10 @@
+-------------------------------------------------------------------
+Tue Nov 23 12:41:51 UTC 2021 - Dr. Werner Fink <werner@suse.de>
+
+- Add patch mailx-12.5-systemd.patch to add description how to avoid
+  bugs like bsc#1192916 -- mailx does not send mails unless run via
+  strace or in verbose mode
+
 -------------------------------------------------------------------
 Wed Jan 27 12:27:13 UTC 2021 - Ludwig Nussel <lnussel@suse.de>
 
diff --git a/mailx.spec b/mailx.spec
index 03fa791..f0370fd 100644
--- a/mailx.spec
+++ b/mailx.spec
@@ -26,7 +26,7 @@ BuildRequires:  postfix
 BuildRequires:  update-alternatives
 BuildRequires:  pkgconfig(openssl)
 Requires(post): update-alternatives
-Requires(postun): update-alternatives
+Requires(postun):update-alternatives
 URL:            http://heirloom.sourceforge.net/mailx.html
 Provides:       mail
 Recommends:     smtp_daemon
@@ -59,6 +59,8 @@ Patch12:        0004-globname-Invoke-wordexp-with-WRDE_NOCMD-CVE-2004-277.patch
 Patch13:        mailx-12.5-openssl-1.1.0f.patch
 #PATCH-FIX-SUSE: bsc#1180355 -- mailx calls sendmail with wrong name
 Patch14:        fix-sendmail-name.patch
+#PATCH-FIX-SUSE: bsc#1192916 - mailx does not send mails unless run via strace or in verbose mode
+Patch15:        mailx-12.5-systemd.patch
 BuildRoot:      %{_tmppath}/%{name}-%{version}-build
 
 %description
@@ -84,6 +86,7 @@ minor enhancements like the ability to set a "From:" address.
 %patch12 -p1 -b .0004
 %patch13 -p0 -b .ssl11f
 %patch14 -p1 -b .sendmail
+%patch15 -p0 -b .systemd
 %patch -p1 -b .0
 
 %build