When you sign up for ListKit Bundles, every technical infrastructure decision has already been made for you. You do not choose your domain extension. You do not choose your inbox provider. ListKit makes those decisions based on what actually works, consistently, at scale, over time.
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This article explains why ListKit provides only .com domains and Google inboxes, and why that is not going to change. It covers the inboxes ListKit provides. You can still connect inboxes you already own.
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The fastest way to start on this stack is ListKit's pre-warmed inboxes: .com domains and Google inboxes that are already warmed, so you can send within minutes. See What are ListKit's pre-warmed inboxes and how do I set them up?
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ListKit could save money by using cheaper domain extensions, .co, .info, .io, .online, and by splitting inboxes between Google and Microsoft or using SMTP-based providers. These options cost a fraction of .com domains and Google Workspace inboxes.
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But here is the reality: cheap alternatives work until they suddenly stop working. There is no warning. One day deliverability drops, emails start landing in spam, and campaigns that were performing well stop performing. Troubleshooting the cause across multiple infrastructure providers is painful, time-consuming, and often inconclusive. ListKit's experience running cold email at scale makes one thing clear: .com domains and Google inboxes are simply what works. Consistently. At scale. Without the sudden failures that cheaper alternatives are prone to.
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The most expensive option is also the one ListKit covers on your behalf. Here is why that decision was made deliberately.
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If the infrastructure fails, your results fail. If your results fail, you cancel. ListKit's interests are directly tied to your campaigns performing well, which means cutting corners on infrastructure to protect margins would be counterproductive.

By including .com domains and Google inboxes in the subscription at no extra cost to you, ListKit removes two of the biggest variables that cause cold email to underperform. You never have to decide between a cheaper domain that might work and a more expensive one that definitely works, because the decision has already been made for you, and ListKit is the one paying for it.
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Every inbox provider, Gmail, Outlook, and others, evaluates the trustworthiness of incoming emails partly based on the sending domain and the infrastructure behind it. .com domains carry more inherent trust than newer or less common extensions.
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Google inboxes are recognized as legitimate sending infrastructure in a way that SMTP-based or Microsoft-split setups are not always able to match consistently.

The result is that your emails are starting from the strongest possible position before a single word of copy is written. Everything else ListKit pre-configures (sending limits, warmup, the 7-day ramp-up, inbox rotation and deliverability settings) builds on that foundation. See What are the expert defaults pre-configured in my Bundles setup?
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You never have to think about infrastructure choices. Your domains and inboxes are set up on the most reliable stack available, managed by ListKit, and covered by your subscription. The only decisions you make are about your audience and your offer, not about which domain extension gives you better deliverability.
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Can I use a domain I already own?
You can connect inboxes on domains you already own, but they are not part of your Bundle's managed setup. Reach out to [email protected] to discuss your options. ListKit's standard setup uses .com domains exclusively, but the team can advise you on the best path forward.
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Can I use Microsoft or Outlook inboxes instead of Google?
The inboxes ListKit provides with your Bundle are always Google inboxes. You can also connect inboxes you already own: open Inboxes, click Connect inboxes and choose Outlook (Hotmail, Live, MSN) (also covers Microsoft 365 business mailboxes), Other (Any provider, IMAP), Google (Gmail / GSuite) or CSV (Bulk Email Addition). See How do I connect my own inboxes to Email Engine? ListKit's data shows its pre-warmed inboxes get about 2.5x the reply rate of self-connected inboxes.
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Why do some other platforms offer cheaper domain options?
Cheaper domain extensions and inbox providers do reduce costs, for the platform and sometimes for the customer. The tradeoff is reliability. They work until they do not, and when they stop working, it is usually without warning. ListKit has chosen not to make that tradeoff.
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Does this affect how my emails look to prospects?
Your prospects see your sender name and the email address you set up in the sender persona step of your Bundle setup, not the underlying infrastructure. What the infrastructure affects is whether your email lands in their inbox or their spam folder.