diff --git a/CHANGELOG.md b/CHANGELOG.md
index 64e232c42..83959c2f3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -35,6 +35,7 @@
 
 ### Changes
 - allow sender timestamp to be in the future, but not too much
+- refactorings #3706
 
 ### Fixes
 - `dc_search_msgs()` returns unaccepted requests #3694
diff --git a/deltachat-ffi/src/lib.rs b/deltachat-ffi/src/lib.rs
index 2b1594a7a..402627206 100644
--- a/deltachat-ffi/src/lib.rs
+++ b/deltachat-ffi/src/lib.rs
@@ -2852,7 +2852,11 @@ pub unsafe extern "C" fn dc_chat_get_mailinglist_addr(chat: *mut dc_chat_t) -> *
         return "".strdup();
     }
     let ffi_chat = &*chat;
-    ffi_chat.chat.get_mailinglist_addr().strdup()
+    ffi_chat
+        .chat
+        .get_mailinglist_addr()
+        .unwrap_or_default()
+        .strdup()
 }
 
 #[no_mangle]
diff --git a/deltachat-jsonrpc/src/api/types/chat.rs b/deltachat-jsonrpc/src/api/types/chat.rs
index f63243112..f5a5c3bcd 100644
--- a/deltachat-jsonrpc/src/api/types/chat.rs
+++ b/deltachat-jsonrpc/src/api/types/chat.rs
@@ -37,7 +37,7 @@ pub struct FullChat {
     ephemeral_timer: u32, //TODO look if there are more important properties in newer core versions
     can_send: bool,
     was_seen_recently: bool,
-    mailing_list_address: String,
+    mailing_list_address: Option<String>,
 }
 
 impl FullChat {
@@ -81,7 +81,7 @@ impl FullChat {
             false
         };
 
-        let mailing_list_address = chat.get_mailinglist_addr().to_string();
+        let mailing_list_address = chat.get_mailinglist_addr().map(|s| s.to_string());
 
         Ok(FullChat {
             id: chat_id,
diff --git a/deltachat-jsonrpc/typescript/generated/types.ts b/deltachat-jsonrpc/typescript/generated/types.ts
index d55bde227..c8d451b44 100644
--- a/deltachat-jsonrpc/typescript/generated/types.ts
+++ b/deltachat-jsonrpc/typescript/generated/types.ts
@@ -22,7 +22,7 @@ export type Contact={"address":string;"color":string;"authName":string;"status":
  * the contact's last seen timestamp
  */
 "lastSeen":I64;"wasSeenRecently":boolean;};
-export type FullChat={"id":U32;"name":string;"isProtected":boolean;"profileImage":(string|null);"archived":boolean;"chatType":U32;"isUnpromoted":boolean;"isSelfTalk":boolean;"contacts":(Contact)[];"contactIds":(U32)[];"color":string;"freshMessageCounter":Usize;"isContactRequest":boolean;"isDeviceChat":boolean;"selfInGroup":boolean;"isMuted":boolean;"ephemeralTimer":U32;"canSend":boolean;"wasSeenRecently":boolean;"mailingListAddress":string;};
+export type FullChat={"id":U32;"name":string;"isProtected":boolean;"profileImage":(string|null);"archived":boolean;"chatType":U32;"isUnpromoted":boolean;"isSelfTalk":boolean;"contacts":(Contact)[];"contactIds":(U32)[];"color":string;"freshMessageCounter":Usize;"isContactRequest":boolean;"isDeviceChat":boolean;"selfInGroup":boolean;"isMuted":boolean;"ephemeralTimer":U32;"canSend":boolean;"wasSeenRecently":boolean;"mailingListAddress":(string|null);};
 
 /**
  * cheaper version of fullchat, omits:
diff --git a/src/chat.rs b/src/chat.rs
index 7bda1598b..6e58d1d2d 100644
--- a/src/chat.rs
+++ b/src/chat.rs
@@ -1130,8 +1130,8 @@ impl Chat {
     }
 
     /// Returns mailing list address where messages are sent to.
-    pub fn get_mailinglist_addr(&self) -> &str {
-        self.param.get(Param::ListPost).unwrap_or_default()
+    pub fn get_mailinglist_addr(&self) -> Option<&str> {
+        self.param.get(Param::ListPost)
     }
 
     /// Returns profile image path for the chat.
diff --git a/src/receive_imf.rs b/src/receive_imf.rs
index 3d078b91a..dc48c5d66 100644
--- a/src/receive_imf.rs
+++ b/src/receive_imf.rs
@@ -1912,7 +1912,7 @@ async fn apply_mailinglist_changes(
             if list_post != old_list_post {
                 // Apparently the mailing list is using a different List-Post header in each message.
                 // Make the mailing list read-only because we would't know which message the user wants to reply to.
-                chat.param.set(Param::ListPost, "");
+                chat.param.remove(Param::ListPost);
                 chat.update_param(context).await?;
             }
         } else {
@@ -2989,7 +2989,7 @@ mod tests {
         assert!(chat.can_send(&t.ctx).await?);
         assert_eq!(
             chat.get_mailinglist_addr(),
-            "reply+elernshsetushoyseshetihseusaferuhsedtisneu@reply.github.com"
+            Some("reply+elernshsetushoyseshetihseusaferuhsedtisneu@reply.github.com")
         );
         assert_eq!(chat.name, "deltachat/deltachat-core-rust");
         assert_eq!(chat::get_chat_contacts(&t.ctx, chat_id).await?.len(), 1);
@@ -2998,7 +2998,7 @@ mod tests {
 
         let chat = chat::Chat::load_from_db(&t.ctx, chat_id).await?;
         assert!(!chat.can_send(&t.ctx).await?);
-        assert_eq!(chat.get_mailinglist_addr(), "");
+        assert_eq!(chat.get_mailinglist_addr(), None);
 
         let chats = Chatlist::try_load(&t.ctx, 0, None, None).await?;
         assert_eq!(chats.len(), 1);
@@ -3057,7 +3057,7 @@ mod tests {
         let chat = Chat::load_from_db(&t.ctx, chat_id).await.unwrap();
         assert_eq!(chat.name, "delta-dev");
         assert!(chat.can_send(&t).await?);
-        assert_eq!(chat.get_mailinglist_addr(), "delta@codespeak.net");
+        assert_eq!(chat.get_mailinglist_addr(), Some("delta@codespeak.net"));
 
         let msg = get_chat_msg(&t, chat_id, 0, 1).await;
         let contact1 = Contact::load_from_db(&t.ctx, msg.from_id).await.unwrap();
@@ -3320,7 +3320,7 @@ Hello mailinglist!\r\n"
         assert_eq!(chat.name, "ola");
         assert_eq!(chat::get_chat_msgs(&t, chat.id, 0).await.unwrap().len(), 1);
         assert!(!chat.can_send(&t).await?);
-        assert_eq!(chat.get_mailinglist_addr(), "");
+        assert_eq!(chat.get_mailinglist_addr(), None);
 
         // receive another message with no sender name but the same address,
         // make sure this lands in the same chat
@@ -3373,7 +3373,7 @@ Hello mailinglist!\r\n"
         );
         assert_eq!(chat.name, "Atlas Obscura");
         assert!(!chat.can_send(&t).await?);
-        assert_eq!(chat.get_mailinglist_addr(), "");
+        assert_eq!(chat.get_mailinglist_addr(), None);
 
         Ok(())
     }
@@ -3402,7 +3402,7 @@ Hello mailinglist!\r\n"
         assert_eq!(chat.grpid, "1234ABCD-123LMNO.mailing.dhl.de");
         assert_eq!(chat.name, "DHL Paket");
         assert!(!chat.can_send(&t).await?);
-        assert_eq!(chat.get_mailinglist_addr(), "");
+        assert_eq!(chat.get_mailinglist_addr(), None);
 
         Ok(())
     }
@@ -3431,7 +3431,7 @@ Hello mailinglist!\r\n"
         assert_eq!(chat.grpid, "dpdde.mxmail.service.dpd.de");
         assert_eq!(chat.name, "DPD");
         assert!(!chat.can_send(&t).await?);
-        assert_eq!(chat.get_mailinglist_addr(), "");
+        assert_eq!(chat.get_mailinglist_addr(), None);
 
         Ok(())
     }
@@ -3452,7 +3452,7 @@ Hello mailinglist!\r\n"
         assert_eq!(chat.grpid, "96540.xt.local");
         assert_eq!(chat.name, "Microsoft Store");
         assert!(!chat.can_send(&t).await?);
-        assert_eq!(chat.get_mailinglist_addr(), "");
+        assert_eq!(chat.get_mailinglist_addr(), None);
 
         receive_imf(
             &t,
@@ -3465,7 +3465,7 @@ Hello mailinglist!\r\n"
         assert_eq!(chat.grpid, "121231234.xt.local");
         assert_eq!(chat.name, "DER SPIEGEL Kundenservice");
         assert!(!chat.can_send(&t).await?);
-        assert_eq!(chat.get_mailinglist_addr(), "");
+        assert_eq!(chat.get_mailinglist_addr(), None);
 
         Ok(())
     }
@@ -3488,7 +3488,7 @@ Hello mailinglist!\r\n"
         assert_eq!(chat.grpid, "51231231231231231231231232869f58.xing.com");
         assert_eq!(chat.name, "xing.com");
         assert!(!chat.can_send(&t).await?);
-        assert_eq!(chat.get_mailinglist_addr(), "");
+        assert_eq!(chat.get_mailinglist_addr(), None);
 
         Ok(())
     }