Mark Glazer: Cold Email Today, A Look At How It’s Evolving

Cold Email Today: A Look At How It’s Evolving

With Email Outreach Expert, Mark Glazer

What inspired you to pursue a career in email outreach and launch Replylead?

I was always into marketing and sales, and curious about tech and how to stay ahead of the curve. What really pushed me was when I noticed a big gap: Almost every company was blasting emails from their primary domain, often without even the basics set up, and it was killing their reputation and even their internal email. I saw that a horizontal email infrastructure system with multiple mailboxes and custom domains was the smarter way [to go] and that idea is what got me to launch ReplyLead.

The game has shifted from blasting volume to carefully managing reputation and making every email count.

How has email outreach changed since you started?

Oh man, I remember how in 2012 (the golden days) you could send hundreds of emails, even up to 500 from one address on your primary domain, and still get 85%–90% deliverability with double-digit reply rates. I was using Microsoft Word’s mail-merge feature, which was about as close as you could get to mass emailing. Then the Chrome extension SellHack came out, and that was a game changer because it pulled emails straight from LinkedIn. LinkedIn’s defense system for automation was super weak, and even though a lot of the work was still manual, you could get ahead because inboxes just weren’t as saturated. A cold email stood out and was taken seriously.

Since then, inbox saturation exploded, automation got smarter, and deliverability rules tightened. Now you’re lucky if you can safely send 5 emails per mailbox a day. Once a domain’s reputation improves, maybe you can push it to 10 or 15, but even then you risk getting flagged, blocked, or bounced. The game has shifted from blasting volume to carefully managing reputation and making every email count.

What changes have you noticed in audience behavior and how people interact with emails?

In the past, people’s attention spans were longer. You know, they were able to read longer emails and simple personalization worked. {First_name} / {Company_Name} variables were enough. Now, it just seems like most skim on mobile, reading the subject line first and deciding whether to even read the actual email. Suspicion around email isn’t new, but today buyers are far more skilled at telling apart mass automation from genuine outreach. People have become more sophisticated and able to spot automation fast.

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What are the components of an effective cold email campaign?

Well first thing, make sure you have the correct email infrastructure in place. That’s the basics, but most companies still don’t have it. This means a proper setup with multiple mailboxes, custom domains, a configured DNS, plain text sending for better deliverability, no links in the first email, open tracking off, and custom domain tracking off.

Next is personalization and style. The email has to sound human and natural, not automated. Keep it short and mobile-friendly because most people are reading on their phone. In B2B, relevancy is even more important than personalization. You need to target the right ICP, build a strong list, and make sure the message actually matters to them.

And finally, the offer. It should be super clear, backed by social proof, and easy to understand. In B2B this usually comes down to three things: can you make them more money or save them money, can you improve their lifestyle or status, and can you save them time, which often ties right back to money.

What common mistakes do sales teams and marketing teams make with email outreach? How can they be avoided?

The biggest one is still outdated infrastructure. Teams send way too much from one domain or one mailbox and then wonder why they’re landing in spam. The next issue is lists. If you’re blasting to generic lists or not verifying them, you’re hurting your own deliverability. For example, if you send 1,000 emails and get 1 reply, ESPs score that negatively.

On top of that, a lot of teams stop after the first touch. The money’s always in the second or third follow-up, but people give up too early.

And finally, the copy. No clear offer, no personalization, emails that read like a robot wrote them, no text variation, and links dropped in the first email, all of that just screams spam.

So it really comes down to four things: outdated setups, weak lists, no follow-ups, and bad copy. If you’re doing those, you’re not going anywhere.

I’d say relevancy matters even more than personalization. You need both, of course, but if the offer isn’t relevant, people just ignore it.

Could you share an example of a particularly successful email outreach campaign you’ve managed?

Sure. I’d say relevancy matters even more than personalization. You need both, of course, but if the offer isn’t relevant, people just ignore it.

One campaign that really stood out was around a big trade show. We scraped the attendee list from LinkedIn, found their emails, and built the campaign around that. The first line was something simple like, “Hey, I noticed you attended this event.” Then we laid out three quick points on how their business could benefit from our service. That style of email still gets strong reply rates today.

For follow-ups, we used an internal tool we built. It’s a browser automation that scores leads in real time and finds alternate contacts with similar job titles at the same company. The opener would be something like, “Hey John, if you’re not the right person, would Mike Smith be a better fit for X?

In what ways have AI and automation transformed lead generation practices at Replylead?

AI has made personalization way faster and more natural. For example, I can scrape a company’s website, feed it into AI, and it’ll give me a first line like, “I was checking out {{company}} and noticed you focus on {{thing}} for {{audience}}.” That feels human, but I didn’t have to spend hours writing it.

It also helps with copy randomization, so you don’t sound like you’re blasting the same template, and with lead scoring, figuring out who’s most relevant. On top of that, we can add in sales triggers, like “Congrats on raising $60M” or “I saw your LinkedIn post on X,” which makes the outreach timely and relevant.

So instead of doing all the manual research and manual tweaks, AI takes care of the repetitive stuff and frees up time to focus on strategy and conversations.

How do you see the future of AI and machine learning shaping outbound marketing and sales?

I’m sure you’ve heard of Sam Altman from OpenAI and Jony Ive, the former Apple Chief Design Officer. They’re working on AI-powered computers, and if that takes off, outreach could look completely different.

Pieces of that future are already here today—scraping data, writing first lines, running sequences—but they’re scattered across platforms and still need a lot of oversight. The vision is to have one device you can just talk to.

You’d say, “Find me new leads in this industry and send a quick intro,” and behind the scenes AI agents would handle it end-to-end: pulling company info, writing a personalized opener, timing the send for when that person usually replies, logging it in your CRM, and setting up the follow-ups.

I mean, I don’t think this replaces people. What it really does is strip away the repetitive work. The change will be toward outreach that’s adaptive, multi-channel, and compliance-aware, while humans focus on the actual conversations that build trust.

How do you stay on top of the latest trends in marketing and sales technology?

I stay current by following industry leaders and testing tools myself. I’m also in peer communities,  Private WhatsApp groups, Slack channels, Reddit. Networking with people doing the same work helps a lot. And honestly, a big part of it is just trying things out firsthand. Experimentation is part of the game, and the future is about building your own tech stack and seeing what actually works.

What advice would you give to sales and marketing teams who feel overwhelmed by rapid changes in outreach technology?

Change is inevitable. I’d tell teams to embrace the change but not get distracted by every new tool. Keep what’s already working as your base, then use AI to build your own tech stack. Start by automating the biggest time drains, test and refine as you go, and stay focused on what actually adds value and drives results.

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About Mark Glazer