diff --git a/packages/nodes-base/nodes/Google/Gmail/GenericFunctions.ts b/packages/nodes-base/nodes/Google/Gmail/GenericFunctions.ts
index 0319df5678ad4..ae0a9e6e7e448 100644
--- a/packages/nodes-base/nodes/Google/Gmail/GenericFunctions.ts
+++ b/packages/nodes-base/nodes/Google/Gmail/GenericFunctions.ts
@@ -166,19 +166,13 @@ export async function parseRawEmail(
 	dataPropertyNameDownload: string,
 ): Promise<INodeExecutionData> {
 	const messageEncoded = Buffer.from(messageData.raw, 'base64').toString('utf8');
-	let responseData = await simpleParser(messageEncoded);
+	const responseData = await simpleParser(messageEncoded);
 
 	const headers: IDataObject = {};
-	// @ts-ignore
 	for (const header of responseData.headerLines) {
 		headers[header.key] = header.line;
 	}
 
-	// @ts-ignore
-	responseData.headers = headers;
-	// @ts-ignore
-	responseData.headerLines = undefined;
-
 	const binaryData: IBinaryKeyData = {};
 	if (responseData.attachments) {
 		const downloadAttachments = this.getNodeParameter(
@@ -196,8 +190,6 @@ export async function parseRawEmail(
 				);
 			}
 		}
-		// @ts-ignore
-		responseData.attachments = undefined;
 	}
 
 	const mailBaseData: IDataObject = {};
@@ -205,14 +197,17 @@ export async function parseRawEmail(
 	const resolvedModeAddProperties = ['id', 'threadId', 'labelIds', 'sizeEstimate'];
 
 	for (const key of resolvedModeAddProperties) {
-		// @ts-ignore
 		mailBaseData[key] = messageData[key];
 	}
 
-	responseData = Object.assign(mailBaseData, responseData);
+	const json = Object.assign({}, mailBaseData, responseData, {
+		headers,
+		headerLines: undefined,
+		attachments: undefined,
+	}) as IDataObject;
 
 	return {
-		json: responseData as unknown as IDataObject,
+		json,
 		binary: Object.keys(binaryData).length ? binaryData : undefined,
 	} as INodeExecutionData;
 }
@@ -390,6 +385,14 @@ export function prepareQuery(
 		let timestamp = DateTime.fromISO(qs.receivedAfter as string).toSeconds();
 		const timestampLengthInMilliseconds1990 = 12;
 
+		if (
+			!timestamp &&
+			typeof qs.receivedAfter === 'number' &&
+			qs.receivedAfter.toString().length < timestampLengthInMilliseconds1990
+		) {
+			timestamp = qs.receivedAfter;
+		}
+
 		if (!timestamp && (qs.receivedAfter as string).length < timestampLengthInMilliseconds1990) {
 			timestamp = parseInt(qs.receivedAfter as string, 10);
 		}
diff --git a/packages/nodes-base/nodes/Google/Gmail/GmailTrigger.node.ts b/packages/nodes-base/nodes/Google/Gmail/GmailTrigger.node.ts
index fe663c2490c87..2634463b2f7a2 100644
--- a/packages/nodes-base/nodes/Google/Gmail/GmailTrigger.node.ts
+++ b/packages/nodes-base/nodes/Google/Gmail/GmailTrigger.node.ts
@@ -194,8 +194,8 @@ export class GmailTrigger implements INodeType {
 		let responseData;
 
 		const now = Math.floor(DateTime.now().toSeconds()) + '';
-		const startDate = (webhookData.lastTimeChecked as string) || now;
-		const endDate = now;
+		const startDate = (webhookData.lastTimeChecked as string) || +now;
+		const endDate = +now;
 
 		const options = this.getNodeParameter('options', {}) as IDataObject;
 		const filters = this.getNodeParameter('filters', {}) as IDataObject;
@@ -273,7 +273,38 @@ export class GmailTrigger implements INodeType {
 			);
 		}
 
-		webhookData.lastTimeChecked = endDate;
+		const getEmailDateAsSeconds = (email: IDataObject) => {
+			const { internalDate, date } = email;
+			return internalDate
+				? +(internalDate as string) / 1000
+				: +DateTime.fromJSDate(new Date(date as string)).toSeconds();
+		};
+
+		const lastEmailDate = (responseData as IDataObject[]).reduce((lastDate, { json }) => {
+			const emailDate = getEmailDateAsSeconds(json as IDataObject);
+			return emailDate > lastDate ? emailDate : lastDate;
+		}, 0);
+
+		const nextPollPossibleDuplicates = (responseData as IDataObject[]).reduce(
+			(duplicates, { json }) => {
+				const emailDate = getEmailDateAsSeconds(json as IDataObject);
+				return emailDate === lastEmailDate
+					? duplicates.concat((json as IDataObject).id as string)
+					: duplicates;
+			},
+			[] as string[],
+		);
+
+		const possibleDuplicates = (webhookData.possibleDuplicates as string[]) || [];
+		if (possibleDuplicates.length) {
+			responseData = (responseData as IDataObject[]).filter(({ json }) => {
+				const { id } = json as IDataObject;
+				return !possibleDuplicates.includes(id as string);
+			});
+		}
+
+		webhookData.possibleDuplicates = nextPollPossibleDuplicates;
+		webhookData.lastTimeChecked = lastEmailDate || endDate;
 
 		if (Array.isArray(responseData) && responseData.length) {
 			return [responseData as INodeExecutionData[]];