A shared sending IP carries traffic from several customers. A dedicated IP carries only your organization's traffic, so you take responsibility for the sending history it builds.
What changes when the IP is yours?
You stop sharing that IP's reputation with other customers. Your own sending practices can build or damage it.
Google's sender guidelines explain that every sender on a shared IP contributes to its reputation. One sender's activity can therefore affect another sender's delivery.
An exclusive IP does not make every reputation signal independent. Microsoft's Outlook.com guidance names the IP, domain, authentication, list accuracy, complaints and content as filtering factors. Moving IPs does not remove those other signals.
When does a dedicated IP help?
Consider one when your regular sending volume can build its own reputation and you need control over the traffic using that IP.
Bird's dedicated-IP guide ties the choice to consistent volume. It says a lightly used dedicated IP builds reputation more slowly than an established shared pool. The guide gives no minimum number of messages that makes the decision for you.
Evaluate your normal sending pattern, including quiet periods. A large monthly total concentrated into occasional campaigns is a different workload from steady daily traffic.
When can it hurt?
Low or irregular volume can make a dedicated IP a poor fit. A new IP also needs a sending history before you ask it to carry a large burst.
Microsoft says new sending IPs typically have no reputation in its systems and are more likely to encounter delivery problems. A new address does not arrive with an established sender's track record.
Google recommends consistent sending, gradual increases and avoiding sudden spikes. Skipping warmup conflicts with that guidance. Before moving traffic, check how you will increase volume and respond to deferrals or bounces.
What does a dedicated IP not fix?
It does not replace authentication, accurate content or a healthy recipient list. Gmail's sender requirements still apply, including authentication and spam-rate requirements.
Fix unwanted subscriptions and misleading content at their source. Changing the sending address leaves those causes intact. Domain warmup is also a separate consideration from establishing an IP's history.
How does Bird handle the move?
You start on the shared pool. Buying a dedicated IP leaves that default unchanged, so unspecified sends keep using the established shared infrastructure.
You choose when to route traffic through a dedicated pool. Bird's default-pool rules keep a purchase from automatically moving all your mail onto a cold IP.
Each new dedicated IP starts in warming. Bird's automatic warmup increases its share of traffic in stages over roughly 30 days. Traffic beyond the warming IP's allowance overflows through the shared pool. Plan for that shared traffic during the ramp.
The warmup guide recommends leaving the shared pool as default until the dedicated IP is active and warmup_completed_at is set. Follow the reported state before changing the default; the approximate duration is not a promised completion date.
You can use separate IP pools for transactional and marketing streams. Pools control which IPs carry each stream. They do not remove the domain, content and recipient signals that mailbox providers also evaluate.
Should you stay shared or move?
- Stay shared when your volume is low or irregular and cannot support a steady sending history.
- Consider a dedicated IP when sustained traffic and control over that IP's senders justify building your own reputation.
- Fix authentication, content and recipient problems before expecting an IP change to improve delivery.
- Warm the new IP and check its state before making its pool the default.