diff --git a/src/error.rs b/src/error.rs
index 26edba4..15ac27e 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -18,6 +18,9 @@ pub enum Error {
     /// No rule for label
     #[error("No rule for label {0}")]
     NoRuleFoundForLabel(String),
+    /// No label found in the mailbox
+    #[error("Label {0} not found in the mailbox")]
+    LableNotFoundInMailbox(String),
     /// Rule not found for ID
     #[error("No rule for id {0}")]
     RuleNotFound(usize),