Improvements (cronmail) and fixes in mail utilities.

.utils/mail/README.md

@@ -1,3 +1,7 @@
-# Wrapper scripts to various mail transfer agents.
-Only needed if your system does not provide the POSIX mailx compatible mail command. If sending email is prohibited from your environment use *mail.dummy* to avoid warnings from cron, etc.
-To activate, choose a suitable one then place it somewhere in the path (~/bin or /usr/local/bin are recommended), name it mail and give it execute permission.
+# Wrapper scripts to various mail agents
+
+Only needed if your system does not provide a local MTA (e.g *sendmail*) and/or a POSIX *mailx* compatible mail command.
+
+To activate, choose a suitable one then place it somewhere in the path (*/usr/local/bin* is recommended), name or symlink it to *mail* and give it execute permission to anyone.
+
+To use them with *crond*, you may need the *cronmail* converter script, which can accept sendmail-formatted mail and convert it into a suitable *mailx* call. You can usually set this script as a mail sender for *crond* using the *CRONDARGS* environment variable.

.utils/mail/cronmail

@@ -0,0 +1,52 @@
+#!/bin/bash
+#
+# This is a sendmail to mailx format converter script.
+# It receives a well-formed email text from standard input, parses it,
+# and invokes a POSIX mailx compliant mail user agent with the result.
+#
+# It is primarily designed to use with crond. To activate
+# use CRONDARGS="-m pathname_to_cronmail" in/etc/default/cron or
+# /etc/sysconfig/crond configuration.
+#
+# Author: Kovács Zoltán <kovacsz@marcusconsulting.hu>
+# License: GNU/GPL v3+ (https://www.gnu.org/licenses/gpl-3.0.en.html)
+# 2026-05-02 v0.1 Initila release.
+
+# Initialisations.
+#
+SUBJECT=""
+RECIPIENT="$USER"			# Default recipient.
+MESSAGE=""
+MUA="/usr/local/bin/mail"		# Custom mail user agent script.
+
+# Parsing the stdin line by line.
+#
+while IFS= read -r line
+do
+    # Parses the recipient.
+    if [[ "$line" =~ ^(T|t)o:\ .*$ ]]; then
+	RECIPIENT="${line#*: }"
+    # Parses the subject line.
+    elif [[ "$line" =~ ^(S|s)ubject:\ .*$ ]]; then
+	SUBJECT="${line#*: }"
+    # Message body starts with an empty line.
+    elif [[ "$line" =~ ^$ ]]; then
+	MESSAGE+="\n"
+    # Collects the message body lines.
+    # The first empty line will be stripped.
+    elif [ -n "$MESSAGE" ]; then
+	[[ "$MESSAGE" = "\n" ]] \
+	&& MESSAGE="$line\n" \
+	|| MESSAGE+="$line\n"
+    fi
+done
+
+# Calls the mail user agent.
+#
+if [ -x "$MUA" ]; then
+    if [ -n "$SUBJECT" -o -n "$MESSAGE" ]; then
+	echo -e "$MESSAGE" | "$MUA" -s "$SUBJECT" "$RECIPIENT"
+    fi
+fi
+
+# That's all, Folks! :)

.utils/mail/mail.dummy

@@ -1,3 +0,0 @@
-#!/bin/bash
-#
-# Dummy file to met the dependencies. Does nothing.

.utils/mail/s-nail

@@ -20,7 +20,7 @@ SMTP_PASS="topsecret"
 
 # s-nail call.
 #
-if [ -x "$(which s-nail 2>/dev/null)" ]; then
+if [ -x "/bin/s-nail" ]; then
     # The recipient's address is the last argument.
     recipient="${@: -1}"
     set -- "${@: 1: $#-1}"
@@ -29,10 +29,10 @@ if [ -x "$(which s-nail 2>/dev/null)" ]; then
     [[ "$recipient" = "$USER" ]] && recipient="$TO"
     [[ "$recipient" = "$USER@$HOSTNAME" ]] && recipient="$TO"
     if [ -n "$recipient" ]; then
-    "$(which s-nail)" -S from="$FROM" -S v15-compat \
-	              -S smtp-auth="login" -S smtp-use-starttls \
-	              -S mta="$SMTP_PROTO://$SMTP_USER:$SMTP_PASS@$SMTP_SERVER" \
-	              -S record="/var/mail/$USER" \
-	              "${@}" $recipient
+    "/bin/s-nail" -S from="$FROM" -S v15-compat \
+	          -S smtp-auth="login" $([[ "$SMTP_PROTO" = "submission" ]] && echo "-S smtp-use-starttls") \
+	          -S mta="$SMTP_PROTO://$SMTP_USER:$SMTP_PASS@$SMTP_SERVER" \
+	          -S record="/var/mail/$USER" \
+	          "${@}" $recipient
     fi
 fi