Sending email attaching log file for systemd services

I have my unit-status-mail.sh script and the unit-satus-mail@.service to send emails if any of interested services fails/restarts.

[unit-status-mail.sh]

#!/bin/bash
#MAILTO="root"
MAILTO="emailtowhom@sendingemail.com"
MAILFROM="my@mail.com"
#MAILFROM="unit-status-mailer"
UNIT=$1

EXTRA=""
for e in "${@:2}"; do
  EXTRA+="$e"$'\n'
done

echo -e "printamos valor UNIT: $UNIT" 
if [ $UNIT == "uwsgi" ]
then
    ENCODED=`uuencode /path/to/attach/file.log file.log`
elif [ $UNIT == "mongod" ]
then
    ENCODED=`uuencode /path/to/attach/file.log file.log`
fi

UNITSTATUS=$(systemctl status $UNIT)

sendmail $MAILTO <<EOF
$ENCODED

From:$MAILFROM
To:$MAILTO
Subject:Status mail for unit: $UNIT

Status report for unit: $UNIT
$EXTRA

$UNITSTATUS

LOG file attached
-----------
EOF

echo -e "Status mail sent to: $MAILTO for unit: $UNIT"

and here I have the [unit-satus-mail@.service]:

[Unit]
Description=Unit Status Mailer Service
After=network.target

[Service]
Type=simple
ExecStart=/bin/unit-status-mail.sh %I "Hostname: %H""Machine ID: %m""Boot ID: %b"

I'm trying to attach to the email the correspondig log file. If I call it manually

/bin/unit-status-mail.sh uwsgi "Hostname: %H""Machine ID: %m""Boot ID: %b"

it works well... email received with the attached log file. Instead when the service launches it automatically, I still receive the email, but NOT the log file.

I don't know what I'm missing, so I would be very thankful for any hints.