diff --git a/packages/rocketchat-ui-message/client/messageBox.js b/packages/rocketchat-ui-message/client/messageBox.js
index 2b125b85bde0..bd1db13e92e3 100644
--- a/packages/rocketchat-ui-message/client/messageBox.js
+++ b/packages/rocketchat-ui-message/client/messageBox.js
@@ -425,19 +425,24 @@ Template.messageBox.events({
 			return instance.isMessageFieldEmpty.set(false);
 		}
 	},
+
 	'keydown .js-input-message': firefoxPasteUpload(function(event, t) {
-		if ((navigator.platform.indexOf('Mac') !== -1 && event.metaKey) || (navigator.platform.indexOf('Mac') === -1 && event.ctrlKey)) {
-			const action = markdownButtons.find((action) => action.command === event.key.toLowerCase() && (!action.condition || action.condition()));
+		const isMacOS = navigator.platform.indexOf('Mac') !== -1;
+		if (isMacOS && (event.metaKey || event.ctrlKey)) {
+			const action = markdownButtons.find(
+				(action) => action.command === event.key.toLowerCase() && (!action.condition || action.condition()));
 			if (action) {
 				applyMd.apply(action, [event, t]);
 			}
 		}
 		return chatMessages[this._id].keydown(this._id, event, Template.instance());
 	}),
+
 	'input .js-input-message'(event, instance) {
 		instance.sendIcon.set(event.target.value !== '');
 		return chatMessages[this._id].valueChanged(this._id, event, Template.instance());
 	},
+
 	'propertychange .js-input-message'(event) {
 		if (event.originalEvent.propertyName === 'value') {
 			return chatMessages[this._id].valueChanged(this._id, event, Template.instance());
diff --git a/packages/rocketchat-ui/client/lib/chatMessages.js b/packages/rocketchat-ui/client/lib/chatMessages.js
index f3de1008a815..57e9c6b496a0 100644
--- a/packages/rocketchat-ui/client/lib/chatMessages.js
+++ b/packages/rocketchat-ui/client/lib/chatMessages.js
@@ -424,6 +424,23 @@ this.ChatMessages = class ChatMessages {
 		}
 	}
 
+	insertNewLine(input) {
+		if (document.selection) {
+			input.focus();
+			const sel = document.selection.createRange();
+			sel.text = '\n';
+		} else if (input.selectionStart || input.selectionStart === 0) {
+			const before = input.value.substring(0, input.selectionStart);
+			const after = input.value.substring(input.selectionEnd, input.value.length);
+			input.value = `${ before }\n${ after }`;
+		} else {
+			input.value += '\n';
+		}
+		input.blur();
+		input.focus();
+		typeof input.updateAutogrow === 'function' && input.updateAutogrow();
+	}
+
 	restoreText(rid) {
 		const text = localStorage.getItem(`messagebox_${ rid }`);
 		if (typeof text === 'string' && this.input) {
@@ -475,30 +492,24 @@ this.ChatMessages = class ChatMessages {
 	}
 
 	keydown(rid, event) {
-		const input = event.currentTarget;
-		// const $input = $(input);
-		const k = event.which;
+		const { currentTarget: input, which: k } = event;
 
-		if (k === 13) {
-			if ((sendOnEnter == null || sendOnEnter === 'normal' || sendOnEnter === 'desktop') && Meteor.Device.isDesktop()) {
-				if (!event.shiftKey && !event.ctrlKey && !event.altKey && !event.metaKey) { // Enter without shift/ctrl/alt
-					event.preventDefault();
-					event.stopPropagation();
-					this.send(rid, input);
-					return;
-				} else if (!event.shiftKey) {
-					return input.value += '\n';
-				}
-			} else if (sendOnEnter === 'alternative') {
-				if (event.shiftKey || event.ctrlKey || event.altKey || event.metaKey) { // Enter with shift/ctrl/alt
-					event.preventDefault();
-					event.stopPropagation();
-					this.send(rid, input);
-					return;
-				}
+		if (k === 13 || k === 10) { // New line or carriage return
+			const sendOnEnterActive = sendOnEnter == null || sendOnEnter === 'normal' ||
+				(sendOnEnter === 'desktop' && Meteor.Device.isDesktop());
+			const withModifier = event.shiftKey || event.ctrlKey || event.altKey || event.metaKey;
+			const isSending = (sendOnEnterActive && !withModifier) || (!sendOnEnterActive && withModifier);
+
+			event.preventDefault();
+			event.stopPropagation();
+			if (isSending) {
+				this.send(rid, input);
+			} else {
+				this.insertNewLine(input);
 			}
-		}
 
+			return;
+		}
 
 		if (k === 9) { // Tab
 			event.preventDefault();