Wrapper scripts to various mail transfer agents added to .utils collection.

.utils/mail/README.md

@@ -0,0 +1,3 @@
+# 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.

.utils/mail/mail.dummy

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

.utils/mail/mail.s-nail

@@ -0,0 +1,38 @@
+#!/bin/bash
+#
+# A simple wrapper script to s-nail. Needs a suitable smarthost.
+# A copy of sent mail is saved in the /var/mail/$USER mbox file.
+# It is recommended to rotate these files e.g via /etc/logrotate.d.
+# See also https://manpages.ubuntu.com/manpages/focal/man1/s-nail.1.html
+
+# SMTP settings - feel free to adjust.
+#
+# Sender's address is fixed - pay attention to the SPF DNS record!
+FROM="no-reply@example.com"
+# Default recipient(s), delimited by space.
+TO="sysadmin@example.com webadmin@example.com"
+SMTP_SERVER="mail.example.com"
+# smtp (for tcp/25), smtps (for tcp/465), submission (for tcp/587).
+SMTP_PROTO="submission"
+# URL escaping required for special characters below.
+SMTP_USER="no-reply%40example.com"
+SMTP_PASS="topsecret"
+
+# s-nail call.
+#
+if [ -x "$(which s-nail 2>/dev/null)" ]; then
+    # The recipient's address is the last argument.
+    recipient="${@: -1}"
+    set -- "${@: 1: $#-1}"
+    # Our scripts may send mails to the local user.
+    # In this case, we need replace the recipient address.
+    [[ "$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
+    fi
+fi