The details
that matter.

Outbound email uses SMTP2GO. You use our API or webmail; we validate the sender domain, permissions, suppression list and usage allowance before submitting the message.

Sending infrastructure is shared. A brand separates your application data and API access; it does not provide a dedicated SMTP2GO account or IP address.

A brand groups sending domains, templates, and suppression entries. API keys can be pinned to one brand so a client integration cannot send as another brand. You can change a brand's name and slug at any time; its domains, addresses and keys stay attached. A teammate can be limited to one brand or several, and you can add or remove brands from their access later.

No. Existing inbound receiving, message storage and attachments use their separately configured transport. Switching outbound delivery does not change your receiving MX records or stored inbox.

First publish the ownership TXT record directly at your DNS provider. Then retrieve and publish SMTP2GO's sender records. The API and dashboard report the required values and verification state; keep the ownership proof published.

No. Sender reputation, recipient consent, message content, and receiving-server policies all affect placement. We validate domain readiness, block suppressed recipients, and report delivery events. Provider acceptance is not proof of inbox delivery.

Use the service for permission-based email. Suppression checks and sending limits apply to every send; provider and service abuse controls can stop sending.

Replies use the original sender or Reply-To and retain threading headers. Forwarding quotes the original plain text. Original attachments are not forwarded automatically; attach explicit base64 content when needed.

The published Free allowance is 3,000 emails per month with a daily cap. It stops at its allowance instead of billing overage. Provider limits and sender verification still apply.

Use an Idempotency-Key with the identical request. Successful responses and uncertain or partial provider submissions are replayed for 24 hours. A new key represents a new send, so check message status before resubmitting an uncertain send under a different key. An in-flight duplicate is refused until the first request completes.

Yes. Unregistering stops this workspace from sending through that domain. Provider registration and DNS records are retained for separate cleanup; review those before removing mail records that other systems may use.