diff --git a/auth/imap.go b/auth/imap.go
index 268cedf..ca1bd0c 100644
--- a/auth/imap.go
+++ b/auth/imap.go
@@ -57,6 +57,7 @@ func (prov *IMAPProvider) doAuth(next http.Handler,
 		http.Error(w, "Invalid username or password", http.StatusUnauthorized)
 		return
 	}
+	conn.Close()
 
 	authCtx := AuthContext{
 		AuthMethod: "imap",