Shared IP
Definition:A shared IP is an email sending server IP address utilized simultaneously by multiple organizations or user accounts to transmit messages.
For cold outbound sending under 15,000 emails/day, never buy dedicated SMTP IPs. Google Workspace and Microsoft 365 shared IP pools carry billions of legitimate human transactions daily, granting your cold emails instant sender trust.
Frequently Asked Questions about Shared IP
Detailed Technical Breakdown
When sending through Google Workspace or Microsoft 365, your messages travel over massive shared IP pools shared with millions of legitimate enterprise users.
This shared volume establishes high trust with receiving mail filters because the IP reputation is anchored by billions of authentic day-to-day business communications.
However, on shared bulk SMTP providers (like low-cost marketing relays), a bad actor sending spam on the same shared IP can temporarily degrade deliverability for all other users on that IP.
Why it matters for Cold Email & Deliverability
Sending cold email via Google Workspace or Microsoft 365 shared enterprise IP pools provides the highest native deliverability for low-to-mid volume outbound.
It eliminates the need to spend weeks warming up dedicated IP addresses.
How to optimize Shared IP
- Use Google Workspace and Microsoft 365 inboxes to benefit from high-reputation shared IP pools.
- Avoid low-cost, unvetted shared SMTP relay providers that host bulk spammers.
- Authenticate your sending domain with SPF and DKIM to ensure domain-level reputation isolation.
- Monitor domain-specific deliverability metrics via Google Postmaster Tools.
Common Shared IP Mistakes
- Using cheap, unauthenticated shared SMTP servers for cold outbound.
- Assuming that a dedicated IP is always better than a high-reputation Google/Microsoft shared IP pool for cold email.
- Failing to configure custom DKIM signing on shared email platforms.
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