Overview

A cold email sequence sends from your connected mailboxes, one step at a time, on a schedule. Several safety limits sit between an enrolled contact and an actual send. When a send is held back, the contact is not lost. Tantra simply reschedules it for later today, tomorrow, or the next open sending window.

This article covers why a sequence pauses itself and how to confirm it is working.

Likely causes

The sender hit its daily limit, so remaining sends move to tomorrow.
The sender hit its hourly limit, so sends move forward about an hour.
The current time is outside the campaign's sending window.
The campaign is paused or archived, so no steps run.
The enrollment is paused, or already reached a final state like replied, bounced, or unsubscribed.
The recipient is on a suppression or unsubscribe list, so the send is skipped.
The sender shows Disconnected, so Tantra cannot authenticate to send.

How limits and windows work

Each sender has a per-day and per-hour send limit. The defaults are 50 sends per day and 25 per hour, and you can lower them per sender on the Accounts page. When a sender reaches its daily limit, the next step for that contact is rescheduled for the following day. When it reaches its hourly limit, the step is pushed forward about an hour so the new hour can start fresh.

Separately, each campaign has a sending window: the days of the week and the hours during which sends are allowed. Outside that window, the step waits until the window next opens. Together these keep your mailboxes under Gmail's limits and protect deliverability.

Step-by-step checks

Open the campaign from Campaigns. Confirm the status badge reads active. If it is paused, resume it. A draft campaign has not started.
Open the Enrollments tab. Use the status filter to review contacts. A contact with status active is still in the sequence. Statuses replied, bounced, unsubscribed, completed, and failed are final and will not send again.
Check the campaign's sending window in the campaign settings. If the current day or time falls outside it, sends wait for the next open window.
Go to Accounts and confirm the sender shows a green Connected badge and the Gmail capable badge. A Calendar-only sender cannot send email. See A sender shows as disconnected.
On Accounts, review the sender's daily and hourly caps. If they are set low, the sequence will pace slowly and pause once a cap is reached.
Check the Overview tab tiles. Rising Sent and Bounced counts confirm the sequence is running. See Suppression lists and unsubscribes if many contacts skip straight to a final state.

What happens next

When a limit or window holds a send, Tantra reschedules the contact automatically. Daily limits push to the next day. Hourly limits push forward about an hour. A closed window pushes to the next open day and hour. You do not need to restart anything. Watch the Sent tile on the Overview tab climb over the following hours as caps and windows reopen.

Troubleshooting

Symptom	Cause	Fix
Sending stopped after a set number of emails	The sender reached its daily limit	Wait for the next day, or raise the sender's daily cap on the Accounts page.
Sends pause and resume in bursts	The sender reached its hourly limit	This is normal pacing. Sends resume the next hour. Raise the hourly cap if needed.
Nothing sends at certain times of day	The current time is outside the sending window	Widen the campaign's sending days or hours, or wait for the window to open.
No sends at all, campaign is draft	The campaign was never started	Start the campaign from the campaign page.
Contacts jump straight to bounced or unsubscribed	The recipient is suppressed or previously opted out	Review your suppression and unsubscribe lists. These sends are skipped on purpose.
Enrollment status is failed	The sender was missing or could not authenticate at send time	Reconnect the sender on the Accounts page, then re-enroll affected contacts in a new campaign.
The sender shows a Calendar-only badge	The service account is not authorized for Gmail on that mailbox	Grant the Gmail send scope in your Google Workspace admin console and re-verify the sender.

FAQ

What are the default sending limits? 50 emails per day and 25 per hour, per sender. You can lower these per sender on the Accounts page.

My daily limit was reached. When will the rest send? The remaining contacts are rescheduled for the next day and resume automatically. You do not need to restart the campaign.

Why do some contacts never get an email? Contacts on a suppression or unsubscribe list are skipped before sending, and contacts that quarantined during launch are excluded. See My contacts were quarantined.

Does a paused enrollment ever resume on its own? No. A paused enrollment stays paused until you resume it. A rescheduled enrollment, held only by a limit or window, resumes automatically.

Can a disconnected sender still send? No. If the sender shows Disconnected, Tantra cannot authenticate to the mailbox and the step fails. Reconnect the sender first.

How do I know it is limits and not a bug? Open the Enrollments tab. If contacts are still active with a future send time, they are waiting on a limit or window, not stuck.

My emails are not sending