Monitor SSL certificate expiry with Google Sheets and SMTP email alerts

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Important notice

This workflow is provided as-is. Please review and test before using in production.

1. Workflow Overview

Who is this for? DevOps engineers, sysadmins, and website owners who manage multiple domains and need proactive SSL certificate expiration monitoring without manual checks. What it does Automatical...

Best for

SecOps automation workflows
advanced n8n builders looking for reusable templates

Tools used

n8n-nodes-base.stickynote, n8n-nodes-base.scheduletrigger, n8n-nodes-base.googlesheets, n8n-nodes-base.code, n8n-nodes-base.executecommand, n8n-nodes-base.if, n8n-nodes-base.emailsend, n8n-nodes-base.noop

Source and attribution

This workflow is cataloged by N8N Workflows and links back to its original n8n.io source page by M Ayoub.

Original n8n.io source

1.1 Workflow description

Title: Monitor SSL certificate expiry with Google Sheets and SMTP email alerts
Workflow name: Monitor SSL certificate expiry with Google Sheets and SMTP email alerts

Who is this for?

DevOps engineers, sysadmins, and website owners who manage multiple domains and need proactive SSL certificate expiration monitoring without manual checks.

What it does

Automatically monitors SSL certificates across multiple domains, tracks expiration status in a Google Sheet dashboard, and sends beautifully formatted HTML email alerts before certificates expire.

✅ No API rate limits — Uses direct OpenSSL commands, so you can scan unlimited domains with zero API costs or restrictions.

How it works

Triggers on schedule (every 3 days at 10AM)
Reads domain list from your Google Sheet
Checks each domain's SSL certificate using OpenSSL commands
Parses expiration dates, issuer info, and calculates days remaining
Updates Google Sheet with current status for all domains
Sends styled email alerts only when certificates are expiring soon

Set up steps

Connect your Google Sheets OAuth2 credentials
Create a Google Sheet with these columns: Domain, Expiry Date, Days Left, Status, Issuer, Last Checked (the workflow matches on the Domain column to update results)
Add your domains to scan in the Domain column
Update the Sheet ID in the Read Domain List from Google Sheets and Update Google Sheet with Results nodes
Connect SMTP credentials in the Send Alert Email via SMTP node
Optionally adjust ALERT_THRESHOLD_DAYS in two nodes: Prepare Domain List and Set Threshold and Parse SSL Results and Identify Expiring Certs (default: 20 days)

Setup time: ~10 minutes

1.2 Logical Blocks

This catalog entry is organized from the workflow JSON. The node-level section below shows the executable blocks available for review before importing the template.

2. Block-by-Block Analysis

Block 1 - Sticky Note - Overview

Type / Role: n8n-nodes-base.stickyNote - stickyNote
Config choices: Version 1

Block 2 - Sticky Note - Data Input

Type / Role: n8n-nodes-base.stickyNote - stickyNote
Config choices: Version 1

Block 3 - Sticky Note - SSL Check

Type / Role: n8n-nodes-base.stickyNote - stickyNote
Config choices: Version 1

Block 4 - Sticky Note - Output

Type / Role: n8n-nodes-base.stickyNote - stickyNote
Config choices: Version 1

Block 5 - Schedule Trigger (Every 3 Days at 10AM)

Type / Role: n8n-nodes-base.scheduleTrigger - scheduleTrigger
Config choices: Version 1.2

Block 6 - Read Domain List from Google Sheets

Type / Role: n8n-nodes-base.googleSheets - googleSheets
Config choices: Version 4.5

Block 7 - Prepare Domain List and Set Threshold

Type / Role: n8n-nodes-base.code - code
Config choices: Version 2

Block 8 - Split Into Individual Domains

Type / Role: n8n-nodes-base.code - code
Config choices: Version 2

Block 9 - Check SSL Certificate via OpenSSL

Type / Role: n8n-nodes-base.executeCommand - executeCommand
Config choices: Version 1

Block 10 - Parse SSL Results and Identify Expiring Certs

Type / Role: n8n-nodes-base.code - code
Config choices: Version 2

Block 11 - Split Results for Sheet Update

Type / Role: n8n-nodes-base.code - code
Config choices: Version 2

Block 12 - Update Google Sheet with Results

Type / Role: n8n-nodes-base.googleSheets - googleSheets
Config choices: Version 4.5

Block 13 - Has Expiring Certificates

Type / Role: n8n-nodes-base.if - if
Config choices: Version 2

Block 14 - Build HTML Email Alert

Type / Role: n8n-nodes-base.code - code
Config choices: Version 2

Block 15 - Send Alert Email via SMTP

Type / Role: n8n-nodes-base.emailSend - emailSend
Config choices: Version 2.1

Block 16 - No Alerts Needed (All Certs OK)

Type / Role: n8n-nodes-base.noOp - noOp
Config choices: Version 1

3. Summary Table

Workflow	Monitor SSL certificate expiry with Google Sheets and SMTP email alerts
Complexity	advanced
Nodes	16
Categories	SecOps
Author	M Ayoub
Published	09 Jan 2026

4. Reproducing the Workflow from Scratch

1. Download the workflow JSON

Use the JSON export at /data/workflows/12607/12607.json as the source template for this automation.
2. Import the template into n8n

Open n8n, import the downloaded JSON, and review each node before activating the workflow.
3. Configure credentials and variables

Replace placeholder credentials, API keys, webhook URLs, account IDs, and environment-specific values with your own settings.
4. Test with sample data

Run the workflow manually or in a staging workspace, inspect node output, and confirm downstream systems receive the expected data.
5. Activate and monitor

Enable the workflow only after testing, then monitor executions, errors, and rate limits during the first production runs.

5. General Notes & Resources

Review imported nodes carefully before activation. This catalog entry is intended to help you inspect the workflow structure, understand required services, and find related templates faster.

Node names, credentials, schedules, webhook paths, and external service limits may need adjustment for your workspace.

Download workflow JSON Original n8n.io source SecOps workflows

Frequently asked questions

What does Monitor SSL certificate expiry with Google Sheets and SMTP email alerts do?

What do I need before importing this workflow?

Review the workflow JSON, configure any required credentials in n8n, and test the automation in a safe workspace before using it in production.

Can I customize this workflow?

Yes. Use the block-by-block analysis and the downloadable JSON to inspect each node, then adjust credentials, prompts, schedules, filters, or destinations for your SecOps use case.

M Ayoub

3 workflows

Nodes

n8n-nodes-base.stickynote n8n-nodes-base.scheduletrigger n8n-nodes-base.googlesheets n8n-nodes-base.code n8n-nodes-base.executecommand n8n-nodes-base.if n8n-nodes-base.emailsend n8n-nodes-base.noop

Complexity

advanced

Published 09 Jan 2026

Likes 0

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Install path: /data/workflows/12607/12607.json

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Monitor SSL certificate expiry with Google Sheets and SMTP email alerts

Workflow preview

Important notice

1. Workflow Overview

Best for

Tools used

Source and attribution

1.1 Workflow description

Who is this for?

What it does

How it works

Set up steps

1.2 Logical Blocks

2. Block-by-Block Analysis

Block 1 - Sticky Note - Overview

Block 2 - Sticky Note - Data Input

Block 3 - Sticky Note - SSL Check

Block 4 - Sticky Note - Output

Block 5 - Schedule Trigger (Every 3 Days at 10AM)

Block 6 - Read Domain List from Google Sheets

Block 7 - Prepare Domain List and Set Threshold

Block 8 - Split Into Individual Domains

Block 9 - Check SSL Certificate via OpenSSL

Block 10 - Parse SSL Results and Identify Expiring Certs

Block 11 - Split Results for Sheet Update

Block 12 - Update Google Sheet with Results

Block 13 - Has Expiring Certificates

Block 14 - Build HTML Email Alert

Block 15 - Send Alert Email via SMTP

Block 16 - No Alerts Needed (All Certs OK)

3. Summary Table

4. Reproducing the Workflow from Scratch

1. Download the workflow JSON

2. Import the template into n8n

3. Configure credentials and variables

4. Test with sample data

5. Activate and monitor

5. General Notes & Resources

Frequently asked questions