diff --git a/src/blob/upload.rs b/src/blob/upload.rs
index d887941..84ba009 100644
--- a/src/blob/upload.rs
+++ b/src/blob/upload.rs
@@ -27,7 +27,7 @@ impl Client {
         blob: Vec<u8>,
         content_type: Option<&str>,
     ) -> crate::Result<UploadResponse> {
-        let account_id = account_id.unwrap_or(self.default_account_id());
+        let account_id = account_id.unwrap_or_else(|| self.default_account_id());
         let mut upload_url =
             String::with_capacity(self.session().upload_url().len() + account_id.len());
 
diff --git a/src/core/changes.rs b/src/core/changes.rs
index 7e4cf51..5bbf892 100644
--- a/src/core/changes.rs
+++ b/src/core/changes.rs
@@ -92,14 +92,26 @@ impl<O: ChangesObject> ChangesResponse<O> {
         &self.created
     }
 
+    pub fn take_created(&mut self) -> Vec<String> {
+        std::mem::take(&mut self.created)
+    }
+
     pub fn updated(&self) -> &[String] {
         &self.updated
     }
 
+    pub fn take_updated(&mut self) -> Vec<String> {
+        std::mem::take(&mut self.updated)
+    }
+
     pub fn destroyed(&self) -> &[String] {
         &self.destroyed
     }
 
+    pub fn take_destroyed(&mut self) -> Vec<String> {
+        std::mem::take(&mut self.destroyed)
+    }
+
     pub fn arguments(&self) -> &O::ChangesResponse {
         &self.arguments
     }
diff --git a/src/email/helpers.rs b/src/email/helpers.rs
index af341cd..d200a6d 100644
--- a/src/email/helpers.rs
+++ b/src/email/helpers.rs
@@ -162,10 +162,13 @@ impl Client {
     pub async fn email_changes(
         &self,
         since_state: impl Into<String>,
-        max_changes: usize,
+        max_changes: Option<usize>,
     ) -> crate::Result<ChangesResponse<Email<Get>>> {
         let mut request = self.build();
-        request.changes_email(since_state).max_changes(max_changes);
+        let changes_request = request.changes_email(since_state);
+        if let Some(max_changes) = max_changes {
+            changes_request.max_changes(max_changes);
+        }
         request.send_single().await
     }
 
diff --git a/src/email/query.rs b/src/email/query.rs
index 0560223..cf701b4 100644
--- a/src/email/query.rs
+++ b/src/email/query.rs
@@ -95,7 +95,7 @@ pub enum Filter {
         value: Vec<String>,
     },
 
-    // Stalwart specific
+    // Non-standard
     Id {
         #[serde(rename = "id")]
         value: Vec<String>,
@@ -121,8 +121,6 @@ pub enum Comparator {
     From,
     #[serde(rename = "to")]
     To,
-    #[serde(rename = "cc")]
-    Cc,
     #[serde(rename = "subject")]
     Subject,
     #[serde(rename = "sentAt")]
@@ -133,6 +131,10 @@ pub enum Comparator {
     AllInThreadHaveKeyword { keyword: String },
     #[serde(rename = "someInThreadHaveKeyword")]
     SomeInThreadHaveKeyword { keyword: String },
+
+    // Non-standard
+    #[serde(rename = "cc")]
+    Cc,
 }
 
 impl Filter {
diff --git a/src/event_source/stream.rs b/src/event_source/stream.rs
index 0187b6e..7c5f0be 100644
--- a/src/event_source/stream.rs
+++ b/src/event_source/stream.rs
@@ -1,4 +1,4 @@
-use std::{pin::Pin, time::Duration};
+use std::time::Duration;
 
 use crate::{client::Client, core::session::URLPart, event_source::parser::EventParser, TypeState};
 use futures_util::{Stream, StreamExt};
@@ -13,7 +13,7 @@ impl Client {
         close_after_state: bool,
         ping: Option<u32>,
         last_event_id: Option<&str>,
-    ) -> crate::Result<Pin<Box<impl Stream<Item = crate::Result<Changes>>>>> {
+    ) -> crate::Result<impl Stream<Item = crate::Result<Changes>> + Unpin> {
         let mut event_source_url = String::with_capacity(self.session().event_source_url().len());
 
         for part in self.event_source_url() {