Do not send from your primary domain
This is the mistake that ends most MCA email programs in week three. Cold volume from the domain your contracts and lender submissions run through puts your entire business communication at risk. Register secondary domains — close variants of your brand — and send from those. If they burn, you replace a $12 domain instead of rebuilding your business email.
Authenticate properly before any volume
SPF, DKIM, and DMARC are not optional. Every sending domain needs all three configured correctly, and DMARC should start at p=none while you monitor reports before tightening. Providers increasingly reject unauthenticated bulk mail outright, so an unauthenticated domain does not get a slow decline — it gets a wall.
Warm up on a real schedule
A new inbox sending 500 emails on day one is a spam signal. Start at 10 to 20 sends per inbox per day and ramp over two to four weeks. Warmup tools help, but the ramp discipline matters more than the tool. Plan on three weeks before real volume.
Cap per-inbox daily volume
Keep each inbox under roughly 50 cold sends per day and add inboxes rather than raising the cap. Ten inboxes at 40 sends beats two inboxes at 200 every time, and it means a single flagged inbox does not take the program down.
Verify before every send, not once a quarter
Business email decays fast — people leave, domains lapse, catch-alls change behavior. Verification at delivery is a starting point, not a guarantee for a file you send six weeks later. Re-verify anything older than 30 days before it goes out.
Watch reply rate, not just open rate
Open tracking is increasingly unreliable thanks to privacy proxies inflating opens. Reply rate and bounce rate are the signals that actually correlate with inbox placement. A bounce rate over 3 percent means stop sending and fix the list.
Keep the copy plain
Heavy HTML, image-heavy templates, multiple links, and link shorteners all raise filtering risk. Plain-text-style emails with a single link, or none at all, land more reliably and — in this industry specifically — read as a real person rather than a blast.
Honor opt-outs immediately and permanently
One-click removal, processed globally, suppressed forever. Beyond the legal requirement, a merchant who asks out and gets emailed again will report you as spam, and complaint rate is the fastest way to lose a domain.
Published 2026-08-14 · MCA Email Leads
