Guides for technical senders, marketers, and support teams living in SMTP.
Isolate transactional vs promo streams, rotate IPs, and keep revenue mail flowing even when blocklists hit.
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Treat transactional, product, support, marketing, and outbound traffic like separate tenants. Give them unique sender identities, IP pools, and authentication. A zero-trust mindset assumes any one stream will eventually get rate-limited or blocked, so isolation prevents collateral damage.
Maintain hot spares for each stream: warmed IPs, pre-validated domains, and DNS templates ready to deploy. Use automation to rotate traffic weekly - even when nothing is on fire - so failover procedures stay tested.
Pipe deliverability telemetry, blocklist alerts, and bounce codes into a rules engine. When a threshold trips, reduce volume or reroute traffic automatically. Manual reviews are too slow when a blocklist listing can tank revenue in an hour.
Store SOPs next to the infrastructure: which DNS hosts to edit, which SMTP creds to rotate, which executives to notify. Back every step with scripts or runbooks so on-call teams can execute without waiting for the one email expert to wake up.
Design for failure, not perfection.
Automate routing decisions before a crisis.
Separate streams keep revenue emails safe.