Who runs this

prewarmed.org is operated by the team behind Warm Inboxes (warminboxes.com) and Upscale B2B (upscaleb2b.com). Orders are fulfilled by Warm Inboxes.

Why this site exists separately

Most of what is written about prewarmed infrastructure is written by people selling it, with no numbers attached, and most of what is sold as prewarmed skips either the aging or the warming. This site exists to state a specific, checkable definition of the term and to document the checks a buyer can run themselves.

We sell the thing we write about. That is stated on every page rather than buried, because a reader who discovers it later is entitled to feel handled, and one told up front is not.

What we operate

Warm Inboxes runs prewarmed and fresh Google Workspace, Microsoft 365 and Azure infrastructure, and sends at volume across its own campaigns. The figures and recommendations on this site come from operating that infrastructure.

The same team runs Upscale B2B, which runs cold email campaigns for clients end to end. That is where a lot of the sending behind these numbers actually happens, and it is why the advice here is written from the position of someone who has to live with the consequences of it.

Corrections

If a number here is wrong, tell us at hello@prewarmed.org and we will fix it and say what changed.