Email infrastructure and deliverability

Infrastructure is the layer that carries an email, and it is not the sequencer job. Treating it as one is the most common reason a campaign dies quietly. Four decisions are made here, all before anyone writes a subject line. Never send cold from your main domain, because reputation damage is not something you undo by stopping, and that domain also carries your invoices and your password resets. Get SPF, DKIM and DMARC written correctly, which is most of what you are paying a provider to automate at the moment a domain is created. Buy enough mailboxes that no single one carries too much volume, and let deliverability decide that number rather than the invoice. And warm up before ramping, which means the honest answer to when can we start is in about three weeks. Pricing here is per mailbox per month, in the two to five dollar range depending on whether it sits on their own infrastructure, on Google or on Microsoft, with dedicated IPs an order of magnitude above that. A dedicated IP is a real decision rather than a default: on low volume, a shared pool is warmer than anything you can build alone. Buy the estate before the campaign, not the week it launches.