SMTP Setup

Connect any email provider (Yahoo, Outlook, Zoho, custom domains) to WarmOpener using SMTP credentials. Perfect for business email addresses and providers without OAuth support.

What is SMTP?

SMTP (Simple Mail Transfer Protocol) is the standard protocol for sending emails. Instead of OAuth, you provide your email server's credentials directly. This allows you to connect virtually any email provider.

Supported Providers

  • Gmail: Also available via SMTP (requires app-specific password)
  • Yahoo Mail: smtp.mail.yahoo.com
  • Outlook/Hotmail: smtp.office365.com
  • Zoho Mail: smtp.zoho.com
  • Custom domains: Check with your hosting provider

Connection Steps

1. Gather Your SMTP Credentials

You'll need the following information from your email provider:

  • SMTP Host: Server address (e.g., smtp.gmail.com)
  • SMTP Port: Usually 587 (STARTTLS) or 465 (SSL)
  • Username: Usually your full email address
  • Password: Your email password or app-specific password

2. Open SMTP Connection Modal

Navigate to Inboxes and click Connect SMTP. A modal will open with a form for your credentials.

3. Enter Your Details

Fill in all required fields:

  • Email Address: Your full email (e.g., john@yourdomain.com)
  • Display Name: Optional - how your name appears to recipients
  • SMTP Host: Your provider's SMTP server
  • Port: 587 for STARTTLS, 465 for SSL
  • SMTP Username: Usually same as email address
  • SMTP Password: Your password (encrypted after save)
  • Use SSL/TLS: Check this for port 465, uncheck for 587

4. Test Connection

Click Connect. WarmOpener will test the connection before saving. If successful, your inbox appears in the list. If it fails, you'll see an error message to fix your credentials.

Common SMTP Settings

Gmail

  • Host: smtp.gmail.com
  • Port: 587 or 465
  • Username: your-email@gmail.com
  • Password: App-specific password (not your regular password)
  • SSL/TLS: Checked for 465, unchecked for 587

Yahoo Mail

  • Host: smtp.mail.yahoo.com
  • Port: 587 or 465
  • Username: your-email@yahoo.com
  • Password: Your Yahoo password or app password

Outlook/Hotmail

Security Note

Your SMTP password is encrypted using industry-standard pgcrypto (PGP symmetric encryption) before storage. WarmOpener tests the connection before accepting credentials to ensure they work. The password is encrypted at rest in the database and only decrypted when sending emails. It is never exposed to the frontend after saving.

For Gmail users: You must create an app-specific password. Regular passwords won't work if 2-factor authentication is enabled. Learn how →

SMTP vs OAuth

FeatureGmail OAuthSMTP
Setup DifficultyEasy (1 click)Medium (need credentials)
SecurityHighest (OAuth tokens)High (encrypted passwords)
Provider SupportGmail onlyAny email provider
Token RefreshAutomaticN/A (uses password)
Business EmailsGoogle Workspace onlyAll domains

💡 Pro Tip

Use Gmail OAuth for the best experience. Use SMTP for Yahoo, Outlook, Zoho, or custom business domains. Both methods work identically once connected - same features, same sending worker, same tracking.

Need help? Email Support
SMTP Setup | WarmOpener Docs | WarmOpener