Sales Talk: Growth via cold email still works, and how to outrun blacklists

B2B growth through outbound has never been more difficult than it is today. Cold outbound isn't what it used to be, before the AI-ification of messaging, the ease of contact discovery and enrichment, and the growth-at-all-costs fervor of well-capitalized startups in 2021.

Mailbox providers (most notably Google and Outlook) cracked down on spray-and-pray email tactics, and an endless list of so-called email blacklists are threatening to turn formerly reliable outbound motions off. But while some blacklists can be ‘lights-out’ for email domains, the reality is that not all will destroy your domain’s reputation. In fact, some businesses end up on blacklists and still maintain strong deliverability.

We spoke with OG outbound infra guru Michael Benson, the CEO and Founder of Mailreef, to cut through the fear and noise surrounding blacklists.

Blacklists aren’t a death sentence: "Not all blacklists are created equal," Benson says. "Anybody in the world can create a blacklist and manually label it as their own. There are blacklists out there literally managed by someone in their basement, handpicking things they don't like. They might have access to larger networks and some degree of validity, but in reality, that's not always the case."

Mailreef created its own infrastructure and platform for cold email, built on the foundation of SMTP technology. With just a few clicks, businesses can set up domains, SPF, DKIM, DMARC, and mailboxes that rival providers like Google, Zoho, and Outlook. Mailreef’s focus is on helping customers diversify their server, domain, and mailbox infrastructure.

"Deliverability relies on three pillars: the server IP, the domain connected to that server, and the mailbox linked to that domain. All three need to be optimized," Benson explains. "Google and Microsoft infrastructures can be flawed and uncontrollable, whereas Mailreef offers a unique structure with a diverse collection of IPs and domains. Spam filters change every three days, which affects infrastructure rankings. At any given time, about 20% of mailboxes are ‘burned,’ regardless of sender quality, so diversification is essential."

Major blacklists to watch: While Benson emphasizes that not every blacklist spells doom, certain major blacklists should raise immediate concern. "Checking blacklists is crucial because being on a major blacklist can cause deliverability issues right away. If your server, domain, or email address is listed, it’s a problem," he warns.

Clarifying which lists matter most. "There are really about three that are almost no-go’s. The moment you find yourself on one of them, you should stop and reassess. One is Spamhaus, the biggest blacklist in the world. Virtually every mailbox provider references Spamhaus, along with SORBS and RAT Spam."

How to avoid blacklists: Benson offers practical advice for companies steering clear of blacklists: "Regularly checking blacklists and conducting deliverability tests are key. Send a generic test email—if it lands in spam, it likely indicates your domain or server is compromised. If it goes to the inbox, your infrastructure is in good shape. If your actual email content lands in spam, it’s probably flagged. Spam filters use fingerprinting to detect flagged signatures. Using AI and Spintax helps because it makes your emails harder to fingerprint and more personalized."

The future of blacklists: For email marketers anxious about being blacklisted, Benson offers reassurance: "You learn from experience. Sometimes you’ll find yourself on a blacklist, but if your deliverability is still strong, that’s a clear sign that not all blacklists matter."

Looking ahead, Benson acknowledges the uncertainty surrounding deliverability. "The truth is, nobody has a crystal ball. I work in email deliverability all day, every day, monitoring metrics across blacklists, reputation networks, Google, Microsoft, and gathering feedback from clients. What will work a year from now? That’s ultimately up to the spam blacklists and reputation monitoring networks, as they decide who’s violating best practices and how to stop them."