Set the maximum emails allowed per day for each warm-up day. The schedule advances one step on each actual sending day. A single active day means that cap applies from day 1 (e.g. 5,000/day immediately).
With the 2-minute drip cadence there are 720 dispatch slots per day. Here's what your batch ceiling can deliver.
Theoretical ceiling at max batch 20: 14,400 emails/day. The relay's limits and your domain reputation (SPF/DKIM/DMARC) still apply.