When to use SMTP

Prefer a Parcel Wing SDK or the HTTP API when you own the application code. Use SMTP for hosted products, legacy apps, CMS plugins, and authentication providers that only accept SMTP credentials.

SMTP settings

Copy the exact values from your in-app Settings page. Most accounts use these defaults.

Security

• Use STARTTLS on port 587.
• Use an active Parcel Wing API key as the SMTP password.
• Rotate the API key if it is pasted into a third-party system you no longer use.
• Keep SMTP credentials in server-side configuration or vendor secret fields.

Test the connection

You can verify the SMTP server accepts STARTTLS before configuring a vendor.

openssl s_client -starttls smtp -connect smtp.parcelwing.com:587

Integration guides

Troubleshooting

• Use port 587 with STARTTLS, not implicit TLS on port 465.
• Use parcelwing as the username and an active Parcel Wing API key as the password.
• Make sure the sender address uses a verified sending domain.
• If a vendor has a test email button, send a test before enabling production email.