Rotation without a pause
The worker fills the first account to its daily limit, then moves to the next by priority. The campaign does not stop, retry, or need a human to notice.
Case studies · Marketing automation
Luny — a campaign that never stops sending
Email sending infrastructure for an Australian cashback platform — seven mailboxes rotated automatically on a rolling 24-hour limit, so a campaign fills one account, moves to the next and never pauses.
12,600Emails a day across the pool
7Sending accounts in rotation
24hRolling window, not a midnight reset
0Sends lost to a full mailbox
The problem
Where it started.
Every mailbox has a daily sending limit, and a campaign that hits it stops. The usual answers are both bad: send under the limit and the campaign takes a week, or send over it and the provider throttles you — which costs deliverability long after the campaign is finished.
The other trap is the reset. Most limits are described as daily, so teams assume capacity returns at midnight and queue everything for 00:01, which is exactly the pattern that looks like a spam run. Real limits move on a rolling window, and the sender has to move with them.
The work
What we built.
A rolling 24-hour window
Capacity comes back gradually through the day rather than all at midnight, so sending stays even and never spikes into a pattern a provider will flag.
Priority, not round robin
Lower number goes first, so the accounts you would rather send from get used before the ones held in reserve.
Health on every account
Sent in the last 24 hours, sent over 30 days, failures over 30 days and when it was last used — per mailbox, on one screen, before anything goes wrong.
Test before you trust
A single test send per account, so a new mailbox is proven from the dashboard rather than discovered mid-campaign.
Add, disable, retire
Accounts are added, paused or removed without touching the campaign running through them.
Gallery
A look at it.
Process
How we ran it.
- 01
Measure the real ceiling
What each mailbox will actually take before a provider throttles it.
- 02
Model the window
The rolling limit first, because reset behavior is what breaks naive senders.
- 03
Build the worker
Rotation, priority and failover, with the campaign never aware of the switch.
- 04
Make it visible
A dashboard the team reads at a glance instead of a log they have to grep.
Outcome
What changed.
7,208Sent in a single 24-hour window
0Failures in 30 days, across every account
12,600Daily ceiling the pool now carries
[Add a quote from Luny — ideally about campaigns no longer stalling on a full mailbox.]
[Name, role, Luny]
Stack
Built with.
- Queue worker
- Rolling rate limits
- SMTP
- Cron scheduling
- Deliverability monitoring
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