You're sitting on a list of 500 prospects you think are perfect for your business. You send out emails to all of them in one week. Then you wait for replies.
Nothing happens. Or worse - you get a handful of replies, but they're from people who weren't really qualified in the first place.
The problem isn't your email copy. It's probably your campaign size.
Most mid-market B2B service businesses and agencies throw way too many emails at their prospects at once. They think bigger lists equal more deals. Then they wonder why their reply rates tank and their sales pipeline looks like a ghost town.
Let's talk about what actually works for mid-market cold email - the real numbers, not the theoretical stuff you read in marketing blogs.
Why Campaign Size Matters for Mid-Market
Here's the thing about cold email - it's not like paid ads where you can just turn up the volume and expect proportional results. Email deliverability, sender reputation, and inbox placement don't work that way.
When you're a mid-market company - meaning you're somewhere between $5M and $100M in revenue, or you're an agency with 15-50 employees - you have a specific advantage. You're not enterprise-sized yet, so you can move fast and test things. But you're big enough that people take you seriously.
Your email sending infrastructure, your domain reputation, and your sending practices all compound. Do them wrong at scale, and you'll tank your ability to reach prospects for months.
The Mid-Market Cold Email Size Benchmark
Based on what actually works for clients at this stage:
- Start with 50-100 emails per campaign
- Keep campaigns running for 7-10 days before pausing to analyze
- Send daily with 10-15 emails per day maximum
- Wait at least 5-7 days between follow-ups on the same prospect
- Never run more than 2-3 active campaigns simultaneously from the same domain
Why these numbers?
First, 50-100 emails per campaign lets you get real data without risking your sender reputation. If you're sending 500 emails a week and your reply rate tanks, you won't know if it's your list quality, your copy, your timing, or your sending practices. With a smaller campaign, the variables are clearer.
Second, spreading sends across multiple days looks natural to mailbox providers. It's how real people send email. Dumping 100 emails in an hour screams