Your list might be four hundred buyers rather than forty thousand consumers, and each one is worth hundreds or thousands a year. That changes everything about how you send. Discounting is out, because your pricing is contractual. Urgency is mostly real: stock levels, order deadlines, seasonal ranges.
Buyers are also reading at work, on a phone, between other jobs. That rewards plain text-led emails with clear numbers, minimum order quantities, lead times and a link to the trade portal. It punishes heavy consumer-style design.
The other difference is decision length. A stockist may see six emails before ordering, and none of them should be pushy. Your job is to stay the obvious supplier when the shelf runs out.