diff --git a/src/components/Composer.vue b/src/components/Composer.vue
index e8c217aeb1..9035972e43 100644
--- a/src/components/Composer.vue
+++ b/src/components/Composer.vue
@@ -705,6 +705,11 @@ export default {
 			required: true,
 		},
 
+		isDraft: {
+			type: Boolean,
+			default: false,
+		},
+
 		requestMdn: {
 			type: Boolean,
 			default: false,
@@ -1329,7 +1334,12 @@ export default {
 
 		onEditorReady(editor) {
 			this.bodyVal = editor.getData()
-			this.insertSignature()
+
+			// Only append signature on opening drafts if alias changed.
+			// Otherwise leads to unwanted or even duplicate signatures.
+			if (!this.isDraft || this.changeSignature) {
+				this.insertSignature()
+			}
 			if (this.smartReply) {
 				this.bus.emit('append-to-body-at-cursor', this.smartReply)
 			}
diff --git a/src/components/NewMessageModal.vue b/src/components/NewMessageModal.vue
index 406d2df9b3..70bf666100 100644
--- a/src/components/NewMessageModal.vue
+++ b/src/components/NewMessageModal.vue
@@ -90,6 +90,7 @@
 						:smime-sign="composerData.smimeSign"
 						:smime-encrypt="composerData.smimeEncrypt"
 						:is-first-open="modalFirstOpen"
+						:is-draft="composerData.draftId !== undefined"
 						:request-mdn="composerData.requestMdn"
 						:accounts="accounts"
 						@update:from-account="patchComposerData({ accountId: $event })"
diff --git a/src/tests/unit/components/Composer.vue.spec.js b/src/tests/unit/components/Composer.vue.spec.js
index f6e7f8b32a..936abfd624 100644
--- a/src/tests/unit/components/Composer.vue.spec.js
+++ b/src/tests/unit/components/Composer.vue.spec.js
@@ -432,4 +432,86 @@ describe('Composer', () => {
 			search: 'alice',
 		})).toEqual(true)
 	})
+
+	it('inserts the signature when composing a new message', () => {
+		const view = shallowMount(Composer, {
+			propsData: {
+				isFirstOpen: true,
+				isDraft: false,
+				accounts: [
+					{
+						id: 123,
+						editorMode: 'plaintext',
+						isUnified: false,
+						aliases: [],
+					},
+				],
+			},
+			mocks: {
+				$route,
+			},
+			store,
+			localVue,
+		})
+		const insertSignature = vi.spyOn(view.vm, 'insertSignature').mockImplementation(() => {})
+
+		view.vm.onEditorReady({ getData: () => '' })
+
+		expect(insertSignature).toHaveBeenCalled()
+	})
+
+	it('does not insert the signature when opening a draft', () => {
+		const view = shallowMount(Composer, {
+			propsData: {
+				isFirstOpen: true,
+				isDraft: true,
+				accounts: [
+					{
+						id: 123,
+						editorMode: 'plaintext',
+						isUnified: false,
+						aliases: [],
+					},
+				],
+			},
+			mocks: {
+				$route,
+			},
+			store,
+			localVue,
+		})
+		const insertSignature = vi.spyOn(view.vm, 'insertSignature').mockImplementation(() => {})
+
+		view.vm.onEditorReady({ getData: () => '' })
+
+		expect(insertSignature).not.toHaveBeenCalled()
+	})
+
+	it('inserts the signature on alias change even when opening a draft', () => {
+		const view = shallowMount(Composer, {
+			propsData: {
+				isFirstOpen: true,
+				isDraft: true,
+				accounts: [
+					{
+						id: 123,
+						editorMode: 'plaintext',
+						isUnified: false,
+						aliases: [],
+					},
+				],
+			},
+			mocks: {
+				$route,
+			},
+			store,
+			localVue,
+		})
+		const insertSignature = vi.spyOn(view.vm, 'insertSignature').mockImplementation(() => {})
+		view.vm.changeSignature = true
+
+		view.vm.onEditorReady({ getData: () => '' })
+
+		expect(insertSignature).toHaveBeenCalled()
+	})
 })