The dedicated IP misconception
One of the most persistent myths in developer email is that purchasing a dedicated IP address instantly improves deliverability. In reality, for 95% of software applications, switching to a dedicated IP decreases inbox placement and increases spam folder routing.
Understanding why requires looking at how mailbox providers like Google, Microsoft, and Yahoo evaluate IP reputation.
The volume math: why low volume on a dedicated IP fails
Mailbox providers use statistical models to calculate IP reputation. If an IP sends only 500 emails on Monday, 0 on Tuesday, and 5,000 on Friday, Google cannot build a stable reputation score. Irregular sending patterns on low-volume IPs trigger automated throttling.
To maintain a healthy dedicated IP, you must send a consistent baseline volume of at least **100,000 to 250,000 emails per month**.
| Monthly Volume | Recommended Setup | Reasoning |
|---|---|---|
| < 50,000 / mo | Managed Shared IP Pool | Benefits from pooled sender volume and high baseline trust |
| 50,000 – 150,000 / mo | High-Reputation Shared Pool | Volume too sporadic for dedicated reputation consistency |
| 150,000 – 500,000 / mo | Dedicated IP Optional | Sufficient volume to maintain standalone IP reputation |
| > 500,000 / mo | Dedicated IP with Warmup | Complete isolation from other senders and custom rDNS control |
The IP warming curve
When you provision a brand new dedicated IP, its initial reputation is neutral/untrusted. If you blast 50,000 emails on day one, ISPs will defer or drop your connections. A proper warmup curve doubles volume daily over 30 days:
Day 1: 50 emails/day
Day 3: 200 emails/day
Day 7: 1,000 emails/day
Day 14: 8,000 emails/day
Day 21: 30,000 emails/day
Day 30: 100,000+ emails/day (Warmed)How SadaSend manages shared pool hygiene
On SadaSend, shared pools are actively monitored: any account that exceeds a 0.08% spam complaint rate or 4% bounce rate is automatically throttled into quarantine pools before it can affect other senders.