Guides for technical senders, marketers, and support teams living in SMTP.
Compare shared IP pools vs dedicated IPs, understand costs, risks, and what reputation really means.
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Shared SMTP relays group many customers onto the same IP clusters. You borrow the aggregate reputation: if neighbors behave, you can ramp fast; if one customer blasts spam, the entire pool absorbs the hit. Vendors mitigate this with throttling and adaptive routing, but you still lack granular control or visibility.
A dedicated block means every inbox provider judges only your traffic. You can ramp volume strategically, maintain consistent sending patterns, and diagnose deliverability issues without wondering whether another tenant is the culprit. The tradeoff is cost - dedicated IPs add monthly fees plus the overhead of managing warmup, monitoring, and backup routes.
Once you're pushing 50k+ emails per day or running multiple outbound/cold programs, shared pools become unpredictable. Watch for repeated throttling, unexplained blocklist hits, or compliance requests triggered by other tenants. Those are your cues to migrate and invest in tooling that automates IP warmup, reputation tracking, and failover.
Regardless of pool type, pair your SMTP provider with seed testing, inbox monitoring, blocklist alerting, and analytics that highlight ISP-level performance. Dedicated senders should layer on automatic IP rotation, BIMI enforcement, and rule-based throttles so mistakes don't burn the new IPs overnight.
Shared pools trade control for convenience.
Dedicated IPs demand monitoring and patience.
Map the costs before you migrate.