Self-serve sequencers
Fine on quiet B2B lists if you already know deliverability. On merchant cash advance they typically hold for a few weeks, then the domains are spent. You still have to write, warm, watch, and build the apply path yourself.
A desk, not a login
When a tool is enough — and when it is not.
If you mail opted-in, low-complaint audiences and you like running the machine, use a tool. If you mail cold MCA names at volume, the machine is the whole problem.
Newsletter ESPs
Built for people who asked to hear from you. Unsolicited MCA mail on a shared IP is the exact use they ban. That is not a bug in the ESP. It is the product they sold to everyone else on the pool.
A calling floor
Works. It also needs seats, scripts, and a manager. Mail reaches more merchants per day if — and only if — it stays on the tray. That is the job we take.
Ready to send
Bring the list. We will fold the letters and fly them in.
Placement to Gmail and Google Workspace is seed-tested. If it drops below 90% after you are at full speed, those days are credited.