OpenSend docs
Warming up a sending domain
Warmup is the process of increasing sending volume gradually so mailbox providers can observe consistent, wanted mail from your domain.
Suggested approach
- Start with your most engaged recipients.
- Send predictable daily volume instead of sudden spikes.
- Watch bounces, complaints, unsubscribes, opens, and clicks.
- Pause increases when complaint or bounce rates rise.
- Keep transactional and marketing traffic clearly separated by content and consent.
OpenSend workflow
Use verified domains, topics, segments, broadcasts, logs, and suppression state to control volume and diagnose issues. For self-hosted deployments, also watch SES quotas and account production access.
What not to do
Do not buy lists, scrape recipients, or re-mail bounced/complained addresses. Warmup cannot fix poor consent or misleading content.