Who This Is For / When to Use
This guide is for Kyrios users who want to send emails through SendGrid instead of the default email service, typically to improve deliverability, sender reputation, or compliance.
Use this when:
SendGrid is your email provider
You need transactional or workflow emails sent via SendGrid
You see sender verification or SMTP authentication errors
How SendGrid SMTP Works in Kyrios
Kyrios connects to SendGrid using SMTP authentication with an API key. SendGrid requires that the sending email address be verified as a Sender Identity before emails can be delivered.
Step 1: Create an API Key in SendGrid
You must generate an API key in SendGrid before connecting it to Kyrios.
To create an API key in SendGrid:
Log in to your SendGrid account.
Navigate to Settings → API Keys.
Click Create API Key.
Enter a name (for example:
Kyrios SMTP).Select Full Access.
Click Create & View.
Copy the generated API key and store it securely.
This API key will be used as the password when connecting SendGrid in Kyrios.
Step 2: Add SendGrid as an SMTP Service in Kyrios
Once the API key is created, connect it inside Kyrios.
To add SendGrid in Kyrios:
Go to Settings → Email Services.
Click Add Service.
Select SendGrid as the SMTP Provider.
Enter the following values:
Username:
apikeyEmail: Your SendGrid login email address
Password: Paste the SendGrid API key created in Step 1
Click Save.
Kyrios will attempt to authenticate SendGrid immediately.
Step 3: Verify a Sender Identity in SendGrid (Required)
SendGrid will not send emails unless the sender email address is verified.
To verify a sender identity:
In SendGrid, go to Settings → Sender Authentication.
Under Single Sender Verification, click Get Started.
Create a sender using the same email address you entered in Kyrios.
Confirm the verification email sent by SendGrid.
The sender email must exactly match the “From” email used by Kyrios.
Common Issues and Fixes
Error: “550 The from address does not match a verified Sender Identity”
This error means SendGrid blocked the email because the sender email is not verified.
How to fix:
Verify the sender email in SendGrid under Sender Authentication
Ensure the sender email matches the email entered in Kyrios
Save the SMTP service again after verification
Emails Fail After Successful Connection
SMTP authentication can succeed even if sender verification is incomplete.
How to fix:
Confirm Single Sender or Domain Authentication is completed
Confirm the sender email matches exactly (no aliases)
Retry sending after verification
Two-Factor Authentication Not Enabled
Some SendGrid accounts require 2FA for API-based integrations.
How to fix:
Enable Two-Factor Authentication in SendGrid
Retry the SMTP connection in Kyrios
Best Practices for SendGrid + Kyrios
Always verify sender emails before sending campaigns
Use the same sender email across workflows and conversations
Rotate API keys periodically for security
Monitor SendGrid activity logs if delivery issues occur