Best Practices

Deliverability tips

• Use a verified sending domain and set up SPF, DKIM, and DMARC.
• Warm up your IP and sending domain gradually when sending bulk email.
• Keep lists clean: remove hard bounces and inactive addresses.
• Personalize messages to improve engagement.

Rate limiting guidance

• CastBrick enforces rate limits per account and per API key. If you hit 429 responses, implement exponential backoff and retry.
• Use parallelism carefully; coordinate with the dashboard's sending rate options for campaigns.

Security recommendations

• Store API keys securely (environment variables, secrets manager).
• Use separate keys for different services and rotate keys periodically.
• Limit scopes and use least privilege when creating API keys.