Cold email infrastructure, provisioned properly

coldemailinboxes.io is an infrastructure service, not sending software. We do not send your campaigns, write your copy, or manage your sequences. We provision the mailboxes those campaigns send from, and configure the DNS that decides whether they arrive.

One order is 100 Microsoft 365 inboxes on a single domain, for $30 a month. Each inbox is set up for three emails per day, which is 300 sends per day per order. Bring your own domain at no extra charge, or we buy one for $12.

Most cold email problems are infrastructure problems wearing a content costume. A missing SPF include, a DMARC record left at p=none, an SPF record that quietly exceeds the ten-lookup limit and returns permerror - none of these announce themselves. Mail simply stops landing.

The same applies to volume. Concentrating sending on one domain means a single reputation event takes the entire operation with it. Isolating batches across separate domains contains the damage.

• You tell us the volume you need. The estimator on the home page converts that into orders, domains and inboxes.
• We register the domains, or connect the ones you already own. You keep ownership either way.
• Microsoft 365 tenants and mailboxes are created, with each inbox configured for a three-per-day sending limit.
• SPF, DKIM and DMARC are configured for every domain, then verified rather than assumed.
• Credentials are handed over. Connect via OAuth or app passwords in Smartlead, Instantly, Lemlist, Woodpecker, Reply.io, Apollo or anything else that speaks IMAP and SMTP.

Deployment typically takes 24 to 48 hours. DNS propagation and tenant provisioning both need time to settle, and rushing that produces batches that look ready but are not.

Agencies running outbound for multiple clients, B2B sales teams scaling past what a primary domain can safely carry, and operators who would rather not spend two weeks registering domains and waiting on record propagation before the first send.

It is a poor fit if you want a sending platform, managed campaigns, or purchased contact lists. We do not provide any of those.

Infrastructure does not excuse the mail sent through it. Accounts used for unsolicited bulk mail to purchased lists, or for anything deceptive, get terminated. That is covered in the acceptable use policy, and it is enforced because reputation is shared: abuse from one sender degrades deliverability for everyone on the same infrastructure.

The guides and reference material on this site are written by Coldy B, who runs cold email infrastructure at coldemailinboxes.io.

The writing comes out of provisioning and operating this infrastructure rather than from research: the sending limits, authentication failures and bounce behaviour described in the guides are the ones encountered running it. Where a claim is measured rather than general practice, the measured results page publishes the numbers behind it, including the campaigns that performed badly.

Questions about the service, or a setup you are not sure we can support: info@coldemailinboxes.io.