Troubleshooting SMTP Email Delivery Issues

Overview

If you are using an external SMTP provider to send emails from your CRM and those emails are frequently failing to be delivered, the most likely cause is a mismatch between the sender email address and the SMTP account you have configured. This article explains how to identify this mismatch, view detailed error messages, and properly verify your sender identity with common SMTP providers.

The Most Common Cause: Sender Email Mismatch

The primary reason for SMTP delivery failures is that the email address you are using as the "From" address does not match the email address associated with your connected SMTP account. Your SMTP provider requires the sender to be authenticated, and a mismatch will typically cause the email to be rejected.

Checking the Error in a Conversation

After you have set up your SMTP provider, you can send a test email from within a conversation. If the send fails, a red triangle warning icon will appear next to the message. Clicking this icon will display a detailed error message. This error is provided directly by your SMTP service and offers the most specific information about why the delivery failed.

If you have confirmed that you are sending from the correct SMTP-integrated email address and the error persists, you should contact your SMTP provider's support team for further assistance, as they can check the delivery status from their system.

Verifying Your Sender by Provider

Each SMTP provider has a unique process for verifying that you are authorized to send from a specific email address. Below are links to setup guides for popular providers.

• Google Workspace (G Suite): Consult your provider's documentation on setting up an alias for Google SMTP.
• SendGrid: Refer to your provider's guide for sender identity setup.
• Zoho: Review your provider's instructions for using Zoho as an SMTP provider.

Frequently Asked Questions

What does it mean if the sender email doesn't match my SMTP email?

It means the "From" address on the email is different from the address you used to authenticate with your SMTP service. Providers usually block these sends to prevent unauthorized use.

How do I fix a sender email mismatch?

You can either change the sender email in your CRM to match the address authenticated with your SMTP provider, or you can follow your provider's procedure to verify the new sender address separately.

What does clicking the red triangle icon show me?

It reveals the specific error message returned by your SMTP provider for that failed send attempt, which often indicates the precise reason for the failure, such as an unverified sender.

Can I mask my sender email and still avoid this error?

Yes, you can use a masked sender address as long as it is either identical to your SMTP-authenticated email or has been separately verified with your provider according to their rules.

Who do I contact if the error persists even after fixing the mismatch?

You should open a support ticket with your SMTP provider. They have access to their delivery logs and can determine if the issue is on their end or with the recipient's mail server.

Does sender verification work the same way across all providers?

No. The process differs by provider. For example, Google Workspace, SendGrid, and Zoho each have distinct methods for verifying sender identities. Always refer to your specific provider's documentation.