Limits protect your sending reputation and the reputation of every workspace that shares the platform. This page lists each limit and what happens when you reach it.
Daily Limit
Each workspace can send a fixed number of emails per day. A new workspace starts at 100. Each recipient counts once, so an email to three addresses in to, cc and bcc counts as three. The count resets at midnight UTC.
Over the limit, the API answers 429 rate_limit_exceeded. A batch is accepted only when the whole batch fits. Settings › Sending shows how much you sent today, and Request Increase asks for a higher limit.
Request Rate
Each API key can make 10 requests per second. Every response carries the ratelimit-limit, ratelimit-remaining and ratelimit-reset headers. Over the limit, the API answers 429 with a retry-after header. SMTP shares the same counter.
Domain Warmup
Warmup applies to campaigns and automations. API and SMTP emails are never held by it. It starts with the first campaign or automation email from the domain and doubles the daily cap each day for 14 days.
| Day | Marketing emails per domain |
|---|---|
| 1 | 500 |
| 2 | 1,000 |
| 3 | 2,000 |
| 14 | 4,096,000 |
| 15 and later | No warmup cap |
Campaigns and automations that reach the cap wait and continue on their own. You can turn warmup off on the domain page.
Sending Pauses
Inboxjot pauses sending when your bounce or complaint rate reaches its threshold.
- Bounce rate of 4% or more
- Complaint rate of 0.08% or more
While sending is paused, new emails fail with 403 forbidden. You can pause and resume sending by hand in Settings › Sending. A pause for a high rate needs support to resume.
Suppressions
A hard bounce adds the address to the suppression list of the workspace. Three soft bounces in 30 days suppress it for a few days. A complaint suppresses marketing email only.
If every recipient is suppressed, the API answers 403. Otherwise Inboxjot
drops the suppressed recipients and sends to the rest. See
Errors for the response body.