fix broken threading issue

Author: martgil

extension/chrome/elements/compose-modules/compose-render-module.ts

@@ -98,9 +98,11 @@ export class ComposeRenderModule extends ViewModule<ComposeView> {
       const thread = await this.view.emailProvider.threadGet(this.view.threadId, 'metadata');
       const inReplyToMessage = thread.messages?.find(message => message.id === this.view.replyMsgId);
       if (inReplyToMessage) {
-        this.view.replyParams.inReplyTo = inReplyToMessage.payload?.headers?.find(
-          header => header.name === 'Message-Id' || header.name === 'Message-ID'
-        )?.value;
+        const msgId = inReplyToMessage.payload?.headers?.find(header => header.name === 'Message-Id' || header.name === 'Message-ID')?.value;
+        if (msgId) {
+          this.view.sendBtnModule.additionalMsgHeaders['In-Reply-To'] = msgId;
+          this.view.sendBtnModule.additionalMsgHeaders.References = msgId;
+        }
       }
       this.view.replyParams.subject = `${this.responseMethod === 'reply' ? 'Re' : 'Fwd'}: ${this.view.replyParams.subject}`;
       if (this.view.useFullScreenSecureCompose) {