After your turboSMTP account is activated, you can start sending emails even if your sender domain is not yet verified. In this case, our system uses a "re-enveloping" technique to allow email delivery without requiring advanced domain configuration.

Technically, this means the envelope sender address is rewritten by our servers to appear as coming from the turbo-smtp.com domain. For example, if you're sending an email from sender@example.com to recpt@example2.com, our servers will automatically rewrite the envelope sender to follow the VERP standard: bounce+rcpt=example2.com@turbo-smtp.com

This modification ensures the message passes SPF checks, since SPF verification is performed on turbo-smtp.com, not your unverified domain.

Additionally, our system adds a Sender header to your email (e.g., Sender: sender=example.com@turbo-smtp.com), allowing it to pass DomainKey/DKIM filters by verifying the signature with our own DNS records.

We also handle bounce management for you. You can:

• Download a CSV file containing bounced addresses from the turboSMTP servers.
• Or, choose to have bounce messages forwarded to you.

At any time, users can switch from this mode to the Send without modification (recommended) directly from the Client Area