diff --git a/TipsShell.md b/TipsShell.md
index 20e521c8..a6c3c8e8 100644
--- a/TipsShell.md
+++ b/TipsShell.md
@@ -432,4 +432,12 @@ Détecter les tabulations
 
 ~~~
 $ grep -P '\t'
+~~~
+
+# Serveur mail
+
+## Avoir vision des différentes erreurs mailq (MAILER-DAEMON)
+
+~~~{.bash}
+(for id in $(mailq | grep MAILER\-DAEMON | cut -d' ' -f1); do postcat -q $id| grep Diagnostic\-Code\:; done) | sort | uniq -c | sort -n
 ~~~
\ No newline at end of file