do not print grep output, refs #20590

tests/test_send_email.sh

@@ -3,9 +3,10 @@
 # envoyer un mail contenant un truc random
 RAND="$RANDOM"
 EMAIL="deployment+$RAND@ubicast.eu"
+echo "Sending email to $EMAIL"
 echo "This is a test email" | mail -s "Test email from `cat /etc/hostname`" $EMAIL
 sleep 10
-grep $EMAIL /var/log/mail.log | grep bounced
+grep $EMAIL /var/log/mail.log | grep bounced > /dev/null
 if [ $? -ne 0 ]; then
     echo "Sending mail failed"
     exit 1