Published 3 November 2026 · By Bram Van Daele, Teneo
The common advice says a dedicated IP only pays off above 100,000 messages a month. We have never applied that rule. Since Teneo started in 2007, every customer has ended up on dedicated IPs. This guide explains why, how a new account gets there without a volume threshold, and what it changes on the day something goes wrong.
The rule, and why we never used it
Ask whether a smaller sender needs a dedicated IP and you will hear the same figure almost everywhere: not below 100,000 messages a month. The reasoning is that a dedicated IP needs steady traffic before mailbox providers form an opinion of it, so a smaller sender does better in a shared pool that already has a name.
We took a different decision on day one in 2007: every customer gets dedicated IPs, whatever their volume. The reason is reputation isolation. We want every customer to hold a full guarantee that their reputation is theirs alone, on the IP side and on the domain side. The 100,000 rule answers a different question (how much traffic does an IP need before it earns a reputation), and we solve that part with routing rather than with a threshold.
What reputation isolation means
- The IP side. Google's sender guidelines put it in one sentence: "The activity of any senders using a shared IP address affects the reputation of all senders for that shared IP address." On a shared IP your delivery depends on neighbours you cannot see. The day one of them imports a bought list, the pool collects the deferrals, and your password resets wait in the same queue as their campaign.
- The domain side. Mailbox providers also keep a record per authenticated domain. Google states that "DKIM and SPF quotas are specific to your domain", separate from the IP quota, which "is shared for all senders that use that IP address". Yahoo says that "each IP and DKIM domain has a reputation", and runs its complaint feedback loop as "a domain based service" keyed on the DKIM signature. Mail signed with your domain builds your domain's history, which is why we treat the signing domain with the same care as the IP (our guide on DKIM key rotation covers keeping that history unbroken).
- One judgment per mailbox provider. Gmail, Microsoft, Orange and every other provider judge what they receive themselves. A sender therefore holds a separate reputation at each of them, under separate rules. One provider can have a problem with a stream that the others accept without a murmur, and the monthly total will never show it. The per-provider picture does.
Isolation on both sides has a practical consequence. When one of those providers changes its opinion of an IP, we know whose traffic caused it, because nobody else's traffic is on that IP.
How a new customer gets to 100% dedicated
A fresh IP has no history, and mailbox providers are careful with addresses they do not know. That caution is the real point behind the 100,000 rule, and the way we handle it does not involve a volume threshold.
A new account starts in one of our good-quality shared pools. Every deferral our servers receive flows into the console as it happens, per customer and per mailbox provider. When we move a customer to dedicated IPs, the console raises their share step by step, only on days with enough volume to count, while we watch those deferrals per provider. It repeats until the customer sends 100% from dedicated space.
Three details matter here.
- The customer's own mail builds the history. We decide how much of it goes to the dedicated IPs and when. The reputation that results is built from real traffic to real recipients, which is the only kind receivers trust.
- The receivers set the pace. When a step produces deferrals, we pause the move and look at why, so the conversation about the list can start before the dedicated IPs carry more of it.
- The customer does nothing. There is no schedule to follow, no volume plan to submit and no ticket to open.
The obvious objection is that a pool everyone leaves cannot keep a good reputation. Ours can, because it is not a holding area where newcomers share an address with other newcomers. The pool is anchored by established, high-volume streams on our network with years of history at the major mailbox providers. A new account's first messages, at most 100 a day on the no-charge plan, are a rounding error against that volume. They neither dent the pool's reputation nor depend on other new accounts for it.
The end state is the same for every sender, small or large: 100% of their mail on IPs that carry nothing else.
What isolation changes when something goes wrong
Every sender has a bad week at some point: an import that should not have happened, a campaign that drew complaints, a form that got abused. What happens next depends on whether that traffic can be told apart from everyone else's.
On our side. The deferral and bounce stream of a customer's dedicated IPs belongs to that customer and nobody else, so a deep dive starts from the right data instead of from a pool's mixed traffic. We find the cause faster and can tell the customer what we see, with their own numbers.
On the provider's side. In our experience, mailbox providers help faster when a problem sender is cleanly isolated from the rest of our ecosystem. A postmaster who sees one IP, one domain and one sender has a contained case and a plain fix to accept. A postmaster who sees a shared IP with many senders has to work out who is responsible first, and every other sender on that IP waits meanwhile.
For the customer's neighbours. A customer sending clean mail from dedicated IPs is never the collateral damage of someone else's bad week. On a shared pool that protection does not exist, however well the pool is run, because the pool is the unit the receiver judges.
The bigger picture
The 100,000 rule describes a trade-off that exists when the vendor puts smaller senders in pools and leaves them there. We never ran that model. Dedicated IPs for everyone cost us more address space and more automation, and the pipeline that moves customers out of the pool exists because of this one decision. We accepted that cost because reputation is the one thing a relay customer cannot buy back once someone else has damaged it.
Google already keeps its limits per DKIM and SPF domain, separately from the IP, and in our judgment the domain that signs your mail will carry more of your reputation with every passing year. That is why isolation at Teneo covers both: your DKIM domain signs only your mail, and once you have moved over, your dedicated IPs carry only your mail.
Reputation that is yours alone starts on the first day. A Teneo console account sends 100 messages a day at no charge, signed with your own domain, so you can see how your mail behaves on our network before you move anything. When your production mail arrives, the move to dedicated IPs follows.
→ Keep the domain side clean: DKIM key rotation · → Open a Teneo console account
Frequently asked questions
Does every Teneo customer get dedicated IPs, even small senders?
Yes. Every customer ends up on dedicated IPs, whatever their monthly volume. This has been the rule since Teneo started in 2007. A new account begins in a good-quality shared pool and moves out of it step by step while we watch how the major mailbox providers respond.
How long before all my mail is sent from dedicated IPs?
The console raises your share step by step, only on days with enough volume to count. When a step produces deferrals we pause it, and we can tell you which provider is deferring and why. It runs without any action on your side.
Is this a warm-up service?
No. Your own mail to your own recipients builds the reputation of your dedicated IPs. The console routes it: it decides how much of your traffic goes to the dedicated IPs at each step, raises that share on days with enough volume, and we watch the deferral data until it reaches 100%.
Is email reputation tied to the IP address or to the domain?
Both, and the balance differs per provider. Blocklists and tools such as Microsoft SNDS work per IP. Google states that its DKIM and SPF quotas are specific to your domain, while the IP quota is shared by all senders on that IP. Yahoo goes furthest toward the domain: it asks senders to segregate mail streams "by IP or DKIM domain", and its complaint feedback loop "only supports DKIM-signed email and is a domain based service". Teneo isolates both sides.
What happens if another sender on the Teneo network has a problem?
Once you have moved to your dedicated IPs, nothing happens to your mail. Their mail is on their own IPs and signed with their domain, so their deferrals, blocklist listings and conversations with postmasters stay with them. Isolation works in both directions.
Sources: Google, Email sender guidelines (support.google.com/a/answer/81126); Yahoo Sender Hub, Best practices and Complaint Feedback Loop pages (senders.yahooinc.com); quotes as published on 25 and 26 October 2026. The Teneo practice described here is our own operating procedure since 2007. No private communications were used.