Where it's set
Each mailbox's Daily Sending Limit lives in its settings under Settings → Mailbox. It's the maximum number of emails PersistIQ will send from that mailbox in a day — across all campaigns combined.
Two layers of throttling
- Campaign level: Daily Prospect Start (default 50) controls how many prospects enter each campaign per day.
- Mailbox level: Daily Sending Limit caps total sends from the mailbox no matter how many campaigns are running.
Choosing your numbers
- New mailbox: start at 10–30/day and increase gradually over several weeks.
- Established mailbox: 50–100/day is a sustainable cold-email range for most providers.
- Never max out your provider's hard limit (e.g. a 2,000/day Gmail allowance is not a cold-email target). Consistent moderate volume beats bursts.
Symptoms your limit is too high
- Rising bounce rates.
- Emails landing in spam (watch replies and open rates in Reporting).
- Provider warnings or temporary blocks on the mailbox itself.
If you see these, cut volume immediately and see Avoiding spam folders.