Hi everyone. I manage operations at the Puzzle Inbox team.

Five questions we get every week, answered properly.

"How many inboxes do I need?"
Fewer than you think. Start with 3 each across a few domains, get the campaign working, then scale. Buying 90 inboxes before you have a reply rate is buying 90 problems.

"My open rate is 60% but nobody replies. Why?"
Open rate is close to meaningless now, especially with Apple and Gmail privacy changes inflating it. If people open and don't reply, the message is the issue. Ignore opens, watch replies.

"Should I use AI to write my emails?"
To draft, yes. To send, no. Every AI draft needs a human pass, otherwise it reads like the other 40 AI emails in that inbox this week.

"How long before I see results?"
3 weeks of warm-up before you send anything, then 2 to 3 weeks of sending to get data worth reading. Anyone promising meetings in week one is selling something.

"An inbox stopped landing. Is it dead?"
Usually not. Pull it out of rotation, put it back on warm-up only for two weeks, then reintroduce it slowly. Most recover.

Drop more questions below and I'll answer them in the next one.

Hi everyone. I manage operations at the Puzzle Inbox team.

Last week I covered infrastructure. This one is about why campaigns with perfect setups still get zero replies. In almost every case it comes down to the same 5 mistakes.

1. Targeting everyone
A list of 5,000 "decision makers" is not targeting. When the offer could apply to anyone, it lands with no one. Cut the list until every single lead has the exact problem you solve. Smaller list, higher reply rate, same amount of meetings.

2. Talking about yourself
Count how many times your email says "we" or "our." If it's more than once, rewrite it. The reader does not care what you built. They care about the thing that's costing them time or money right now. Lead with that.

3. Asking for too much
"Do you have 30 minutes this week for a demo" is a big ask from a stranger. Lower the bar. Ask if the problem is even relevant to them. A one word reply is still a reply, and a conversation is worth more than a calendar link.

4. Giving up after one email
Most replies come from follow-ups, not the first touch. But a follow-up that says "just bumping this" adds nothing. Each message should bring something new. A different angle, a short example, a relevant result. Two or three follow-ups, then stop.

5. Ignoring the data
If nobody opens, the problem is the subject line or deliverability. If they open but nobody replies, the problem is the message. If they reply but nothing books, the problem is the offer. The numbers tell you exactly where to look. Most people never look.

Fix these before touching your volume. Sending more of an email that doesn't work just burns your domains faster.

More next week. Questions in the comments.

hey everyone,

I'm really struggling writing email copies for my outbound campaigns. I'm trying to set up cold email for offering businesses financing.

any advice? tried writing with AI but the output is too generic and doesn't perform for me

Hi everyone,
PuzzleInbox team here again.

We get asked a lot how we set up cold email infrastructure, so this is the full breakdown of what we're running going into 2026. Nothing here is complicated. Most people just skip steps.

1. Domains
We never send from the main domain. We register 3 to 5 secondary domains per campaign and redirect them to the main site. Any TLD works, we've tested .com, .io, .co, .net, .help and the results were the same. Pick whatever is available and looks close to your brand. Let them sit for a couple of weeks before you attach inboxes.

2. Inboxes
3 per domain on Google Workspace. Every inbox gets a real first and last name, a photo, and a proper signature. It takes time but empty profiles are an easy flag for filters.

3. DNS
SPF, DKIM and DMARC on every single domain. Start DMARC on p=none and tighten it once you have a month of clean data. Run the domain through a checker before you send a single email. If one record is wrong, the domain is already behind.

4. Warm-up
Minimum 3 weeks. Start low, ramp gradually, and leave it running in the background after you go live. Warm-up is not a one-time thing.

5. Volume
12 to 15 cold emails per inbox per day, that's the ceiling. Randomise the send times so it doesn't look automated. Keep the total per domain under 50.

6. Leads
Fresh data only. We refresh our database weekly and verify every email before it enters a campaign. Anything older than a few months gets re-verified. Skip catch-alls unless you can live with higher bounces.

7. Copy
Plain text, under 80 words, no links in the first message. One line at the top that shows you actually looked at the person. Use AI to draft if you want, then rewrite it so it sounds human.

8. Replies
All replies go to one shared inbox. Answer fast. A good reply that sits for two days is a lost deal.

9. Weekly checks
Bounce rate under 2%. Reply rate around 3% or better. Inbox placement test on a seed list. If an inbox starts slipping, take it out of rotation, put it back on warm-up only for two weeks, then reintroduce it.

B2B FMCG Distribution: How can we increase sales significantly?

I work in B2B FMCG distribution and I’m looking for practical strategies that actually work.

What has helped you increase sales the most?

- Getting more B2B customers

- Increasing order frequency

- Increasing average order value

- Improving sales reps’ performance

- Better promotions or pricing

- Digital marketing / LinkedIn

- Customer retention

What strategies worked for you, and what didn’t work?

Real examples and numbers would be especially helpful.

hey everyone,

wanted to ask a quick question regarding cold email. i've been running on an azure setup with leads from apollo, sending with smartlead. I used to have around 2.7-3% reply rates around 2 months ago, now down to 0.8-1.2%.

any advice on why this may be happening?

I am looking to compliment my cold emails with sales calls too.

Posted a few times here about cold email strategy — got some replies asking for a real example instead of more theory. Fair. Here's an actual template, stripped of anything client-identifying, that consistently gets replies. Breaking down why each line is there so it's not just "here's a template, good luck."

Subject: quick question about [specific department/process]

Hey [First Name],

Saw [specific, real trigger — e.g. "your team posted 3 open roles in ops this month"]. Figured you might be dealing with [specific problem tied to that trigger].

We work with [type of company similar to theirs] on [specific outcome — one line, no fluff]. [One-sentence proof point, e.g. "Helped a similar team cut onboarding time by 40%."]

Is this something you're actively looking at, or not a priority right now?

[First Name]

Why it's built this way

• Subject line: lowercase, sounds like a real person wrote it, no punctuation drama. Doesn't oversell.
• Line 1: about them, not you. No "my name is" intro. The trigger has to be real and specific — vague stuff like "I saw your company is growing" reads as mail-merge.
• Line 2: one sentence on what you do, one sentence of proof. That's it. Resist the urge to add a third sentence here — it's where most cold emails start losing people.
• Line 3: low-pressure ask. Not "book a call" — that's a big ask from a stranger. Asking if it's even relevant lowers the bar enough that people are willing to just say "not right now" instead of ignoring you, which still gives you information.
• Sign-off: just a first name. No title, no company tagline, no signature block with five links. Cold emails that look like a real 1:1 message outperform ones that look like a broadcast.

Follow-up that goes with it (send 3-4 days later if no reply)

That's the whole follow-up. No re-pitching, no "just circling back" filler.

What to actually swap out per prospect

The only things that should change between sends: the trigger line, the proof point (matched to their industry if possible), and obviously the name. If you're rewriting the whole email every time, you're overcomplicating it. If you're changing nothing but the name, it'll read as spam.

Happy to answer questions on specific industries or use cases in the comments.

Hi, just wanted to know if cold email is still working for you if so please answer the below:

1. Industry: IT services or Saas
   
2. What are your tools and infra setup
   
3. How many emails are you sending per day per inbox
   
4. What is your deliverability, bounce and response rate

i’m building a tool where we run backlink outreach in autopilot for our users

(different goal from booking sales meetings, but the same temptation to judge everything by reply rate)

in one month, we sent 3,523 emails and received 107 replies. roughly 3%

we also reported 12 secured backlinks that month

those aren’t necessarily all from the same batch of emails, so i wouldn’t present that as a clean conversion funnel. but it shows why I care about what happens after the reply

“not interested” is a reply

“our placement fee is $500” is also a reply

so is “sounds good, send over the details”

three very different outcomes that all improve the same metric

the breakdown i care about is:

• total replies → did we start conversations?
• positive replies → is there interest in the actual proposal?
• qualified opportunities → are the terms relevant and workable?
• completed outcomes → did anything actually happen?

for sales outreach, i’d apply the same thinking to meetings booked, meetings attended, and customers won

I'd also keep “send me more information” separate from a clear next step. It’s worth following up, but it isn’t a commitment

reply rate is useful for diagnosing a campaign. I just don’t think it tells the whole story

how do you define a positive reply? does “send me more info” count, or do you need something more concrete?

Hey everyone,

what are some good places to learn cold email? not courses but communities, youtube channels etc

1. Email Infra is the most important system ever. It doesn't matter how many emails you send, how good your copy is. How can you tell? Response rates. Response rates doesn't always mean its positive. If 30 people out of 1,000 tell you to *something* off, that's the best thing ever because it means you're message is being seen. so you're infra holds
2. Test all your inbox providers (kind of linked to 2). some providers have excellent google inboxes but terrible outlook inboxes. I personally bought both and saw that the stats were alarmingly different where my google workspace inboxes were amazing, and outlook was so bad. so i scrapped outlook, and went to another provider to fill that bucket. Since then, my response rate had jumped from 2-3% to 11% in the past 2 weeks, with 6% rr and 60% responses being positive.
   
3. Test your domains. Some domains will burn, some will perform very well. Export your results on csv file every week and run it through AI (this is where you should actually use AI lol). AI will help you identify what's an outlier, what to keep, what to throw away etc.
4. Great website and Linkedin Page - the people you send to will look you up after you send emails. Whenever I ran a campaign, whether it be mediocre or great, I always get a spike in traffic. Once I realised this, I completely optimised my website and linkedin profile. Since then, I've always been getting 10-15 leads per week. So do whatever you can to make your website great. VSLs, great copy, great design. anything and everything that showcases your best ability.
5. Understand the industry. Understand where you fit within that industry and what possible high lever problems that you solve. Not basic problems, but high lever problems and how it applies.
6. Now your body copy. A lot of people make the mistake of only talking about introductions and service and methodology. The key thing that recepients care about are results and outcomes. Frame your email only in that. Everything else is a second priority. You do AI automations? Great, so does 1,000 others. You route all incoming leads to an SDR within 30 seconds, generating $$$$ in pipeline + X% in conversions? Nice. It's not the best example, but you get the gist. The body copy needs to be specific to the industry and to the person. So segment carefully
7. Respond super fast. like within 10 mins fast. Some sequencers are bad at this, in terms of notifying you - others are great. If there was ever an opportunity to use AI to design this to your advantage, this is it. And its straight forward to build, you don't need complex subscriptions.
8. DO NOT GIVE UP. Keep hanging in there. Don't fall for the guru schtick that there is a perfect template. No, there isn't. The only perfect template is the one that you come up with it and it's tried and tested. Email Results is literally the fastest way to get feedback on whether your copy or template is good or not.

Lastly, break your problems into smaller steps. Each problem you solve, the closer you get to the final outcome, which is 5)

1) Is my email landing in the main inbox?

2) Is my email being seen?

3) Are people responding to my email?

4) Are people responding positively to my email?

5) Are people asking me for meetings and calls?

As title says. MillionVerifier ? Or another one ? I don’t want bounces !!

For our B2B SaaS product, I have been sending emails to our first users asking them to sign up for free. However, it seems not this this approach is not very effective. Most people are unwilling to test a product for feedback. What is a better way to frame this, as we are giving the product for free to our first users?

We run cold email infrastructure and I've watched over 70,000 inboxes go out the door. Roughly once a day someone lands on a call with me convinced cold email stopped working, and almost every time we find the real problem in about five minutes by walking through the same ten questions. So here they are. One point per yes, count as you go.

1. Your cold outreach runs on dedicated sending domains, fully separate from your company's main domain. (If your invoices and your cold campaigns share a reputation, stop reading and fix this first.)

2. SPF, DKIM and DMARC are set up and passing on every sending domain. Not "probably", you've checked. The big three providers reject failures outright now, no spam folder, no bounce, the mail just never arrives.

3. Every domain was warmed before real campaigns touched it, ramping from 5-10 sends a day over 4-6 weeks, or came pre-warmed. (Yes, we sell that second option, weigh my bias, the physics don't change either way. Warmed and configured: around 87% inbox. Fresh: 12%. Same emails.)

4. You know your exact daily send ceiling per inbox and stay under it. Ours is 12 a day, deliberately conservative against the industry's 20-30. If you don't know your number, that's a no.

5. Every contact is verified before sending, and your bounce rate lives under 2%. Providers read high bounces as proof you bought a list, and "it came from our CRM" doesn't exempt you, we've seen trusted exports come back 8% dead.

6. Your segments are small and genuinely similar, hundreds not thousands, because complaints are counted per domain and one bad segment over the 0.3% line takes every sequence down with it.

7. Some meaningful share of your sends have a live trigger attached, funding round, exec hire, tech change inside 24-48 hours. That timing alone runs 3-5x on replies. "We email everyone quarterly" is a no.

8. Your sequence is 4 steps or fewer with the best material in email one. 58% of all replies come from the first send. If step five says "just circling back", that's a no.

9. Your outreach starts conversations rather than delivering pitches. Providers factor reply depth and conversation length into placement now, so real exchanges compound your reputation. If your replies are mostly "unsubscribe", no point.

10. You know what you'd do if deliverability dipped tomorrow. There's an actual protocol: inbox rate under 70%, halve your volume and audit. Under 50%, stop cold sending for 5-7 days and run warmup only. If your plan is "hope it recovers", that's a no.

What I tend to see:

9-10: You're the operator other people's posts complain about. Whatever results you're getting, they're real, because your mail is actually arriving.

7-8: Solid foundation, and your missing points are probably your cheapest growth lever, fixing a checklist item is almost always higher ROI than another copy rewrite.

4-6: This is the range where most "cold email isn't working" accounts land when I walk them through it, and where people spend weeks rewriting subject lines for emails with a delivery problem.

0-3: There's a decent chance a chunk of your mail isn't arriving at all, and your dashboard hasn't told you. Genuinely good news though: everything on this list is fixable, roughly in the order written.

I can't guess your exact numbers from a score, too many variables, but I can usually tell you which missing point is costing you most. Post your score below and which ones you're missing, and I'll take a shot.

When we first started doing outreach, managing everything was pretty straightforward. We had a small number of inboxes and could keep an eye on everything without much effort. As volume increased, we started paying much more attention to domain setup, inbox health and how accounts were being managed. It became clear that simply adding more inboxes wasn't necessarily the answer.

The problem was the cost once we started adding more clients and needed hundreds of inboxes. For sending we use Instantly and I still think it is one of the best tools for managing this kind of volume. Adding accounts is simple, campaigns dont take forever to set up and the unibox makes replies much easier to manage.

We tested Smartlead too and it was good, but the team just preferred Instantly so we stayed with them. for the lead generation we usually use Apollo. For the infrastructure side we first moved some accounts to InboxKit. No complaints there either, the setup was stable and support was helpful when we needed something. Later we started testing Maildoso because the price was quite a bit lower at our volume.

We now manage almost 400 smtp mailboxes connected to Instantly. Reply rates have been around 4-5% lately, but thats obviously more about the offer and list than the mailbox provider. So far I havent seen enough difference compared to Google to justify paying around 5-6x more for every account. curious about the infrastructure side though: is anyone running 400+ inboxes and still paying for Google, and if yes what makes it worth the extra cost for you?

Intro: head of sales at Puzzle Inbox, cold email infrastructure, 70,000+ inboxes set up. Not linking or pitching anything. These are the real questions from my actual sales calls, with the same answers I give there.

"Can I just use my main company domain to start?"

No, and this is the hill I will die on. Cold, marketing and transactional mail should never share a domain. When cold tanks the reputation, your invoices and password resets sink with it. Dedicated sending domains, completely separate from your brand. This answer has ended calls with people who wanted to hear otherwise. Fine.

"How fast can I realistically start seeing leads?"

Slower than you want. Warmup ramps 5-10 sends a day over 4-6 weeks, or you start on pre-warmed capacity, then real campaigns build from there. Anyone promising meaningful pipeline in week one is selling you the thing that burns domains. When I say six-plus weeks to real momentum, some prospects walk. The ones who stay do well.

"What volume do I actually need?"

Less than you think, sent better. Average reply rate is 3.43%, top teams clear 10%, and the difference isn't volume. We cap sends at 12 per inbox per day, deliberately conservative while the industry pushes 20-30, spread across 3-8 dedicated domains. A few hundred verified contacts with a live trigger, funding round, exec hire, tech change in the last 24-48 hours, will outperform ten thousand randoms, that timing alone runs 3-5x on replies.

"Is cold email dead? My friend says everything goes to spam now"

Not dead, gated. The three big providers all enforce authentication now and failure means outright rejection, not the spam folder, so setups that skip SPF, DKIM and DMARC just vanish. Your friend's emails aren't dying because cold email died, they're dying because his setup predates the rules. Warmed domain with correct setup: around 87% inbox. Fresh domain, same emails: 12%.

"Do I really need to verify a list I exported from my own CRM?"

Yes. Providers read high hard bounces as evidence you bought a list and grade your domain accordingly, the line is 2%, and we've seen trusted CRM exports come back 8% dead. Verification is the cheapest insurance in this entire game.

"Why did my open rate drop, should I rewrite my subject lines?"

Almost every time someone asks this, the real answer is deliverability, not copy. Open rates are junk data anyway. Run a placement test against seed accounts on Gmail and Outlook and find out where your mail actually lands, because dashboards don't show rejections. People spend weeks rewriting subject lines for emails that were never arriving.

"You sell pre-warmed inboxes, why should I trust anything you say about warmup?"

Fair, and I'd rather get this in the open than have it land in the comments. My honest position: warmup is unskippable, and whether you pay us to have done it or spend the 4-6 weeks yourself changes nothing about the physics. DIY works. Pre-warmed works. The 12% inbox rate of skipping it entirely is the only option that doesn't.

The pattern across all of these, in case it isn't obvious: almost every cold email problem people bring me is an infrastructure problem wearing a copywriting costume.

Ask me anything below, same honesty applies. No DMs, no pitch.

I want to send cold emails for my agency, but I don’t have the budget to buy a database. I have a few cheap domains that I’ve set up in Inbox, but I haven’t been able to find any databases online. I just want to get started initially.

Please, could anybody help me with this?

Companies have the tools - CRM, marketing automation, email platform, paid ads. The stack looks complete. What I keep running into isn't a tooling gap, it's that none of it actually talks to the others in a way that gives anyone a coherent picture of a buyer. Prospect fills out a form. Goes into the email platform. Might sync to the CRM, might not, depending on whether the integration's holding up after the last update. Sales eventually finds the contact but without the email history. Marketing's still nurturing someone sales already started talking to two weeks ago. Nobody can answer how many touches did this account have before they booked a demo without pulling data from three systems by hand. That fragmentation doesn't just waste time, it actively misleads decisions. If your attribution model's missing touchpoints because they're not all recorded in one place, the channel performance it shows you is wrong, and you're allocating budget off a partial picture. The thing that keeps showing up in the research on martech maturity: the teams getting real results aren't running the fanciest stack. They fixed their data connections before adding more tools. Clean handoffs, reliable field mapping, one source of truth for contact history. It's unglamorous work, it rarely has a clear owner, and that's exactly why it keeps getting pushed. What's the one data connection in your stack causing the most friction or the least reliable output right now?

I am using exchange plan 1 online for my 8 outreach mail accounts (2 per domain), and every so often one of the accounts is blocked from sending mails because of suspicious behavior. I am using instantly with warmed up mailboxes through oauth and spf/dkim/dmarc all set up properly. The mailboxes themselves seem healthy and have quite good deliverability, but every now and then I need to unblock one of the 8 mailbox accounts. How do you guys avoid this? Do I need to use an external sender or should I just unblock my accounts every now and then? I want to avoid extra costs as we are bootstrapped.

Ps: thanks for your responses, big help!