SendGrid

Twilio SendGrid

Enterprise-grade transactional email service. 100 emails/day on the free tier; paid plans start at $19.95/mo for 50k emails.

Easy~5 minAPI

Quick Reference

Settings

Provider

SendGrid

Auth

API Key (Mail Send permission)

From Email

Must be a verified sender or domain

Prerequisites

• A SendGrid account. Free tier (100 emails/day) is fine for testing.
• A verified sender — either a single email address or a domain with DKIM records.

Step-by-step

Verify a sender

In SendGrid → Settings → Sender Authentication.

For a single sender (quick): Single Sender Verification → fill in your email address → confirm via the email SendGrid sends you.

For a domain (recommended for production): Domain Authentication → enter your domain → SendGrid gives you 3 CNAME records → add to your DNS → click Verify.

Create an API key

SendGrid dashboard → Settings → API Keys → Create API Key.

• Name: SendGrail
• Permissions: Restricted Access → enable only Mail Send (full access for that one scope). Tighter security than Full Access.

Click Create & View. SendGrid shows the API key once — copy it now.

Add the connection in SendGrail

WordPress admin → SendGrail → Connections → Add Connection → pick SendGrid.

Fill in:

• Connection Name: SendGrid
• From Email: the sender you verified in step 1
• From Name: your display name
• API Key: paste the key from step 2

Click Save.

Test

SendGrail → Test Email → pick the SendGrid connection → send.

Troubleshooting

Unauthorized / 401

The API key is wrong or expired. Generate a new one in SendGrid → Settings → API Keys.

403 The from address does not match a verified Sender Identity

Your From Email isn't verified in SendGrid. Either verify that exact address (Single Sender) or verify the parent domain (Domain Authentication).

429 Too Many Requests

You've hit your plan's rate limit. Free tier: 100/day, 600/hour. Upgrade or throttle.

Emails marked as spam by Gmail

Add a verified domain (not just a single sender) so SendGrid signs outbound mail with your domain's DKIM key. This dramatically improves deliverability.

What's next

• Email Routing — route marketing emails through SendGrid while keeping transactional on a faster provider.
• Failure Alerts — get pinged in Slack/Telegram if SendGrid starts rejecting.