I started a cold email campaign 10 days ago; initially it was booming, but then replies dropped and I got a warning about excessive bounces. Should I pause the campaign? What could be causing the dips in replies?
The reason your campaign started strong then declined is that your deliverability decreased over time. When deliverability drops, fewer emails reach inboxes, more get marked as spam, which further hurts deliverability—a negative feedback loop. This usually happens because either your email copy is poor, causing recipients to mark you as spam, or you're sending to a low‑quality list. To fix it, improve your copy and clean your list. Many people use email validation tools like mails.so to check DNS records and get a deliverability score; you can set a cutoff (e.g., only send if >50% deliverable) to automatically remove bad addresses. This cuts out bounces and boosts deliverability and campaign health, though it adds cost (you pay for the validation service), takes extra time to set up, and reduces your lead pool—often to about 30% of the original list after validation. So you trade some volume for better quality and fewer bounces.
When you see high bounce rates, the first thing to do is verify your email list. Depending on how you generated the list, you can use third‑party verification tools such as MailerCheck, ZeroBounce, or similar services that give you a deliverability score. Set a minimum threshold—if a contact falls below it, don’t send to them. Proper verification can eliminate roughly 50 % of bounces. I have free credits through Maker School and other deals, so you don’t have to pay a lot. My typical process is to send a small test batch of 1‑2 k emails to identify which niches or copy combinations perform poorly, then verify the good ones and scale the campaign. This way you only pay for verified emails that are likely to convert.
The drop you’re seeing is likely due to something specific in your campaign rather than a general trend. It could be that you imported multiple audiences into the same CSV and one audience performed much better than the others. Once you exhausted the stronger audience, the overall reply rate would fall off a cliff. Another possibility is that the messaging you used became less effective because others started using the same approach. Also, double‑check your deliverability – make sure you’ve verified inbox placement with tools like Glock Apps. These are the first three things I’d check. If this is your first campaign, remember that even a modest 1‑2 leads per day is enough to be profitable and to iterate on your system.
I start with two emails in total: one main email and one follow‑up. The reason is to put yourself in the shoes of someone reading a crappy email. Think about how many times you’ve opened a pitch email, marked it as unread, or ignored it. If the email isn’t good, a follow‑up makes the recipient far more likely to mark it as spam—about 100× more likely after the first follow‑up and a thousand times after a second. The number one thing we’re trying to avoid in cold email is being marked as spam. So, before you know your copy is good, do not add more than one additional follow‑up, spaced about 48 hours apart. Once your copy is acceptable—say a 3 % reply rate or a 0.5–1 % positive reply rate—you can add more follow‑ups. Adding them will raise your total reply rate, though the proportion of positive replies may drop, the absolute number of positive replies will still increase.
The issue is deliverability getting crushed, similar to cold calling. I run Clarvo, a power dialer that improves pickups, analogous to instant and cold email platforms. A common pattern: you start a campaign with a high pickup rate (e.g., 10%), it’s strong for the first three days, then each day the rate drops by 2‑3 %, quickly falling to 0.5‑1 % and you get squashed. This happens because big carriers and call registrars see the number making many calls, deem it illegitimate, lower its ranking and mark it as likely spam; the same occurs with your emails. Assuming this isn’t isolated, it repeats each time you send. Even if you think it’s not a deliverability problem, there are several causes: (1) Volume – you might be sending slightly too many emails per day. (2) Bounce – a percentage of emails bounce due to invalid servers, leading Gmail and Outlook to suspect automation. (3) Certain words trigger naive spam filters (the algorithms they use to judge legitimacy). (4) Recipients marking you as spam adds a signal that Google, Outlook and other platforms use; even one spam complaint per day out of 200 emails can significantly hurt deliverability over time. Additionally, ESPs, registrars and platforms continually tighten their filters; previously you could send 20‑40 emails per mailbox per day, now you need to stay around 15‑20, raising outreach costs. To test whether your emails are landing, avoid open‑rate tracking (it harms deliverability) and don’t track your main reply‑rate campaign. Instead create a separate campaign—for example, a free podcast campaign—pretend you’re a big YouTuber with a million followers and invite people to be on your podcast. Virtually nobody says no, giving you an easy “yes” to benchmark email performance with a real‑sounding offer (even if you can’t actually fulfill it). This bypasses deliverability placement tests, which are often unreliable. I personally run such a campaign constantly or turn it on when I suspect mailbox issues, directing a few emails to a compliment and an invitation to my podcast (which has over a million subscribers).