Best Free Online Mail Merge Software

Mail Merge Toolkit is a powerful browser-based bulk email solution designed for HR teams, recruiters, schools, businesses, and marketers who need to send personalised emails at scale. Generate custom PDF attachments from Word templates, connect your Excel sheet, and send hundreds of emails in minutes.

Unlike traditional mail merge software, this toolkit works completely online. You do not need to install desktop software, browser extensions, Outlook add-ins, or third-party applications. Everything runs securely inside your browser.

Why this tool is different:

No software download required
No Outlook plugin or add-in needed
Completely browser-based
Free with unlimited usage
Supports Gmail, Outlook, Zoho, Hostinger, Rediffmail, cPanel, and custom SMTP
Create personalised PDF offer letters, certificates, invoices, and increment letters

Upload Files

Map Fields

Preview

Send

Upload your Email Body template and Excel data. PDF Attachment template is optional. Use {{ColumnName}} as placeholders in Word files.

Verify each placeholder maps to an Excel column. Mismatches will appear blank in the output.

Previewing row 1 / 1

✉ Mail Body

📄 PDF Attachment Preview (optional)

🔒 SMTP Configuration

⚡ Quick fill — select your email provider:

Popular

Indian & Regional

Hosting & Custom Domain

SMTP Host

Port

Encryption

Your Email Address (From address)

From Name

App Password — not your regular password

Email column in Excel

Subject column in Excel (optional)

CC column in Excel — column name containing CC address(es)

Fixed CC — always CC these addresses (comma-separated)

📚 How to generate an App Password — step-by-step guide ▼

Gmail

Go to myaccount.google.com/security
Under How you sign in to Google, click 2-Step Verification and enable it if not already on
Return to the Security page → scroll down → click App passwords
Under Select app choose Mail; under Select device choose Other and type "Mail Merge"
Click Generate — copy the 16-character password shown (spaces don't matter)
Paste it in the App Password field above

SMTP Host: smtp.gmail.com | Port: 587 | Encryption: TLS

🔒 After use: Go back to App passwords and delete "Mail Merge". Revoked instantly, zero residual access.

Outlook / Microsoft 365

Go to account.microsoft.com/security
Click Advanced security options
Under App passwords click Create a new app password
Copy the generated password and paste it above

SMTP Host: smtp.office365.com | Port: 587 | Encryption: TLS

⚠ If your organisation has disabled SMTP AUTH, ask IT to enable it for your mailbox, or have them whitelist this server's IP.

🔒 After use: Delete the app password from the same Advanced security options page.

Yahoo Mail

Sign in to Yahoo → click your profile name (top-right) → Account Security
Enable Two-step verification if not already on
Scroll to Generate app password → select Other App → name it "Mail Merge"
Copy the generated password and paste it above

SMTP Host: smtp.mail.yahoo.com | Port: 587 | Encryption: TLS

🔒 After use: Return to Account Security and revoke the "Mail Merge" app password.

Zoho Mail

Go to accounts.zoho.com → Security → Two-Factor Authentication and enable it
Navigate to App-Specific Passwords → click Generate New Password
Enter name "Mail Merge" → copy the password shown
Paste it in the App Password field above

SMTP Host: smtp.zoho.com | Port: 587 | Encryption: TLS

🔒 After use: Delete the password from Zoho Account Security → App-Specific Passwords.

Rediffmail / Rediffmail Pro

Log in at mail.rediff.com
Go to Settings → Mail Settings → enable POP3 / SMTP Access
Rediffmail does not use app passwords — use your regular Rediffmail password directly in the App Password field above
For Rediffmail Pro (business), use smtp.rediffmailpro.com and your Pro account credentials

Rediffmail — Host: smtp.rediffmail.com | Port: 587 | TLS
Rediffmail Pro — Host: smtp.rediffmailpro.com | Port: 587 | TLS

⚠ Rediffmail may block SMTP from new IPs. If sending fails, log in to Rediffmail webmail and look for a security alert email to whitelist your server.

Hostinger Mail

Log in to hpanel.hostinger.com
Go to Emails → select your email account → Set Up Devices
Find SMTP settings — Host is smtp.hostinger.com, Port 587
Use your full email address as Username and your email account password in the App Password field
Alternatively use Port 465 with SSL encryption

SMTP Host: smtp.hostinger.com | Port: 587 (TLS) or 465 (SSL)

⚠ Hostinger does not use app passwords. Use your email account password. If sending fails, check that SMTP is not blocked under Hostinger's firewall settings.

cPanel / WHM / Custom Domain Mail

Log in to your hosting control panel (cPanel) — typically at yourdomain.com:2083 or cpanel.yourdomain.com
Go to Email Accounts → select your account → click Connect Devices or Set Up Mail Client
Note the Outgoing Server (SMTP) — usually mail.yourdomain.com
Use your full email address as Username and your email account password in the App Password field
If Port 587 fails, try Port 465 with SSL, or Port 25 (some hosts block 587)

SMTP Host: mail.yourdomain.com | Port: 587 (TLS) or 465 (SSL)
GoDaddy: smtpout.secureserver.net | Port: 587
Bluehost / SiteGround: mail.yourdomain.com | Port: 587

⚠ Many shared hosts limit the number of emails per hour (50–500/hr). For large merges, consider a transactional email service like SendGrid, Mailgun, or Amazon SES instead.

🔒 After use: Change your email account password from cPanel if you're concerned about credential exposure, especially on shared servers.

💡 General security best practices

App passwords are as powerful as your real password for sending email — treat them with equal care
Never paste them into spreadsheets, emails, or version control
Always revoke immediately after your mail merge is complete — it takes under 30 seconds
Use a descriptive name ("Mail Merge – June 2026") so you can identify and remove it later
If you need to run merges regularly, consider asking your IT team to set up a dedicated service account

Frequently Asked Questions

Is this Mail Merge Toolkit free?

Yes. This is a completely free online mail merge tool with unlimited usage. There are no downloads, subscriptions, or installation requirements.

Do I need Outlook or an Outlook add-in?

No. Unlike most mail merge software, this toolkit works entirely online in your browser. You can use Gmail, Outlook, Zoho, Hostinger, custom domains, and other SMTP providers.

Can I send PDF attachments in bulk?

Yes. The toolkit automatically generates personalised PDF attachments for every recipient using your Word template and Excel data.

What file formats are supported?

You can upload Word templates (.docx, .doc, .txt) and Excel or CSV files (.xlsx, .xls, .csv).

Online Bulk Email Sender for Businesses & HR Teams

Whether you need to send offer letters, appointment letters, salary increment letters, invoices, certificates, admission emails, or marketing campaigns, Mail Merge Toolkit helps you automate bulk communication professionally.

This online mail merge software eliminates the need for expensive desktop applications and complicated Outlook integrations. Simply upload your templates, connect your Excel sheet, preview the output, and send personalised emails instantly.