A brand-new sending mailbox that suddenly blasts hundreds of cold emails looks exactly like a compromised account to a mailbox provider. Laureo prevents that with a managed ramp: each mailbox starts at a conservative daily volume and increases in stages as its connection ages and continues to send clean, low-bounce mail. The ramp is automatic — you do not configure it, and you cannot push a mailbox past its current stage.

Each campaign carries its own optional Daily send limit for this campaign, set in the sequence's settings. It caps the number of new cold emails that one campaign sends per day, totaled across every mailbox that campaign rotates through. Leave it blank (the field reads “No limit”) and the campaign has no limit of its own, so it sends as fast as the mailboxes and the ramp allow.

Because the limit is per campaign, you can run several campaigns at different paces at once: give a priority campaign a higher limit and a background campaign a lower one. One caveat: campaigns that share a mailbox share that mailbox's daily budget, so two campaigns sending through the same mailbox draw from the same per-mailbox allowance rather than each getting a full one.

Alongside the daily send limit, a campaign's settings carry three controls that shape its first-touch volume and its ordering. They pace how a campaign opens new conversations without touching the follow-ups already in flight.

Sends are placed inside each recipient's business hours, computed from their timezone, so your email arrives when a person is actually at their desk rather than at 3 a.m. their time. Within the window, Laureo adds jitter— randomized spacing between sends — so a mailbox never fires a burst of identical-looking messages on a fixed cadence. The result reads like a person sending one email at a time, not a machine.

Some days you would rather not land in a cold inbox at all, such as public holidays. Under Cold Outreach settings, the Skip datescard holds an org-wide list of days cold outreach should not send. A send that would otherwise fall on a skip date is deferred to the next day inside its send window, evaluated in the recipient's timezone, so the message waits for the next legal opening instead of going out on the blackout day. Until it sends, the row stays pending and makes no forward progress.

Each campaign can override the org list. In the sequence builder's schedule, the Skip datesfield starts empty, which inherits your organization's list; add a date there and this campaign uses its own list of blackout days instead, leaving every other campaign on the org default.

Laureo also paces by recipient root domain. Sending too many messages too quickly to the same company domain looks like an attack to that company's mail server, so volume to any single root domain is spaced out. A higher-volume threshold (around 5,000 messages per day to one root domain) applies to large consumer domains. This keeps you from tripping a recipient organization's own rate defenses.

Mail often lands more reliably when the sending mailbox and the recipient sit on the same email provider. When capacity allows, Laureo prefers a first-touch send from one of your mailboxes hosted on the recipient's own provider. This is automatic, with nothing to configure, and it never holds a send: when no matching mailbox has room, or the recipient's provider cannot be determined, sending falls back to the normal rotation across your pool. It only ever changes which mailbox inside its budget sends the email, never whether the email goes out.

Laureo watches each mailbox's rolling bounce rate. If it climbs above 2%, the mailbox is automatically paused for new cold sends — a high bounce rate is the fastest way to get a domain blacklisted, and pausing early protects the mailbox. Replies still send while a mailbox is paused; only new cold steps hold. You resolve the cause (usually a stale or unverified slice of your list) and resume. See Troubleshooting for the resume flow.

Open tracking is off by default on every cold sequence, and for cold outbound we recommend leaving it off. Open tracking adds a tracking pixel to each email, and two things work against it. The numbers are unreliable, because image-blocking and automated link-and-image scanning fire opens that no human ever made. And the extra tracking can itself weigh on deliverability. The signal that actually predicts pipeline is the reply, so track replies and let opens stay off. See Analytics for why reply rate is the headline metric.

As you scale up, how you arrange mailboxes across domains matters as much as the raw count. Best practice is 2 to 3 mailboxes per domain, spread across several sending domains, rather than piling many mailboxes onto one domain. If a single domain picks up a reputation problem, only the mailboxes on that domain are affected and your other domains keep sending. It also keeps the volume on any one domain modest, which is how real senders look. See Domain Setup for authenticating each sending domain.

Many cold-email tools advertise automated “warmup” — networks of mailboxes that email each other and auto-reply to fake an engaged sending history and trick spam filters into trusting a new mailbox. Laureo deliberately does not offer warmup, and here is the honest reasoning.