Sending limits and auto-pause

The always-on limits that keep your sending healthy, and what to do when sending pauses automatically.

Overview

Transactional Email protects your sending reputation with a few limits that are always on and can’t be changed. Two of them affect single sends. The others watch your account as a whole and pause all sending when something looks wrong — a workflow suddenly enrolling far too many contacts, or bounces and complaints climbing. A Super Admin resumes sending once the cause is fixed.

Limits on individual sends

Limit	Rule	What happens
Per recipient	At most 5 emails to the same address in any rolling 24 hours	The sixth send fails with `recipient_rate_limited`.
Burst	At most 10 sends per second for your account, and no faster than HubSpot’s API allows for your account	Extra sends wait their turn and then go out, so a very large workflow enrollment takes a while to work through. Other accounts aren’t slowed down.

Warm-up adds a daily limit during your first 30 days of live sending. See How warm-up works.

Auto-pause

Transactional Email checks your live sending every 15 minutes and pauses it when either rule trips:

Rule	Trips when	Shown as
Unusual volume	Today’s sends are more than 5 times your daily average over the previous 14 days (counting only days you sent) and more than 10% of your included emails plus the extra emails your auto-buy budget can buy	Paused: unusual volume
Bounce or complaint rate	Over the last 7 days, more than 4% of your emails bounced or more than 0.08% were marked as spam — once you’ve sent at least 100 emails in that window	Paused: bounce or complaint rate

Amazon SES, the service that delivers your email, can also pause your account under its own reputation policy. That shows as Paused by Amazon SES. If SES lifts its pause on its own, sending still stays paused until a Super Admin resumes it.

The volume rule needs some history: it only applies once you have at least 3 days of sending in the previous 14.

While sending is paused

Every send fails with tenant_paused (Sending paused). Paused sends aren’t queued or retried.
App Home and Settings show a Sending is paused banner with the reason and when it happened.
Your alert recipients get an email: “Email sending is paused.” You get at most one per pause reason per day.

Resume sending

Find the cause. For unusual volume, look for a workflow whose enrollment triggers changed or that re-enrolls contacts. For bounces and complaints, check that your workflows only email people who expect to hear from you, at current addresses. App Home’s Reporting shows your 7-day bounce and complaint rates against the thresholds.
Fix it. Turn off or correct the workflow, or clean up the contact data.
Click Resume sending in the Sending is paused banner on App Home or Settings, and confirm with Yes, resume sending.

Sending restarts right away. Re-enroll the records whose sends failed with tenant_paused if they still need the email. If the problem continues, sending pauses again.

Only Super Admins can resume sending. If Amazon SES itself suspended sending for your account, Resume sending can’t lift it: you’ll see “Amazon SES suspended sending for this account. Contact support to have it reinstated.” Email support@cambiumapps.com and we’ll work with Amazon to restore it.