diff --git a/melib/src/backends.rs b/melib/src/backends.rs
index 242cf0a18..695fa599d 100644
--- a/melib/src/backends.rs
+++ b/melib/src/backends.rs
@@ -609,7 +609,11 @@ impl std::convert::TryFrom<&[EnvelopeHash]> for EnvelopeHashBatch {
 }
 
 impl EnvelopeHashBatch {
-    fn iter(&self) -> impl std::iter::Iterator<Item = EnvelopeHash> + '_ {
+    pub fn iter(&self) -> impl std::iter::Iterator<Item = EnvelopeHash> + '_ {
         std::iter::once(self.first).chain(self.rest.iter().cloned())
     }
+
+    pub fn len(&self) -> usize {
+        1 + self.rest.len()
+    }
 }