7 deadly sins of email deliverability - pt. 2

Hey there,

Kevin here from Astris Partners with edition 14.

Last week, we covered the first four deadly sins destroying your email deliverability: using your main domain, missing authentication, skipping warm-up, and spray-and-pray messaging.

This week, I'm revealing the final three sins that are quietly sabotaging your campaigns - and they're more subtle than you think.

Deadly Sin #5: Triggering Both Types of Spam Filters

Most people think spam filters only care about obvious words like "free" or "buy now." It's way more sophisticated than that.

There are actually two types of spam filters you need to worry about: technological and psychological.

Technological filters scan for trigger words, but they also analyze context. Words like "guarantee," "exclusive," "limited time," and even "opportunity" can hurt you depending on how they're used.

Psychological filters are your prospect's brain. If your subject line sounds like every other sales email they've seen, they'll hit spam before reading a word.

Overpromising like "increase your revenue by 500% in 30 days" triggers their "too good to be true" detector, which is incredibly common in 2025.

The fix: Run your copy through spam checkers, but more importantly, read it out loud. Would you respond to this email if you received it?

If it sounds like a typical sales pitch, rewrite it to sound like a genuine business conversation. You're not trying to sell or book a call - you're just trying to see if there's interest.

Deadly Sin #6: Making Your Emails Look Like Marketing

Adding logos, fancy images, multiple links, or highlighting your awards might seem professional, but to email providers, it screams "promotional content."

Every image, every link, every design element adds to your spam score. A plain text email that looks like a genuine business message has a much higher chance of getting through. An email that looks like a marketing campaign gets filtered.

The worst offender: Open tracking. That invisible pixel that fires when someone opens your email can actually land you in spam.

The fix: Keep emails plain text:

• No images

• Minimal links

• No fancy formatting

• Don't track open rates

• Focus on what matters: reply rates and positive reply rates

Everything else is vanity metrics that hurt deliverability.

Deadly Sin #7: Robotic Sending Patterns

If you're sending emails exactly at 9:00 AM, 9:03 AM, 9:06 AM every day, you look like a bot. Email providers notice these patterns and treat your emails accordingly.

The same goes for volume. Going from zero emails to 200 emails per day overnight is a massive red flag. It's like someone who's never exercised trying to run a marathon - it's not natural.

The fix: Randomize sending times with 5-15min variations and gradually increase sends.

Begin with 5 emails per day for the first week, then gradually increase over time. This mimics natural human behavior and keeps you under the radar.

The Complete Deadly Sins Recap

Let me recap all seven deadly sins one more time:

Sin #1: Using your main domain for cold email

Sin #2: Missing email authentication (SPF, DKIM, DMARC)

Sin #3: Skipping domain and mailbox warm-up

Sin #4: Spray and pray messaging

Sin #5: Spam words and overpromising (both filter types)

Sin #6: Marketing-style design elements

Sin #7: Robot-like sending patterns

The Stakes

Fix these issues and your deliverability rate will soar. Ignore them and you'll keep wondering why your cold email campaigns generate zero results.

We've seen companies go from blacklisted domains to 30%+ reply rates just by addressing these fundamental mistakes.

Remember: your reputation is everything in email deliverability. One wrong move can take months or years to recover from. But get the fundamentals right, and you'll have a sustainable competitive advantage.

The Bottom Line

Most companies focus on clever subject lines and perfect personalization while completely ignoring these technical fundamentals.

They're optimizing the wrong thing. You can't polish your way out of deliverability problems - you have to fix the foundation first.

Get these seven sins handled, and then worry about optimization. Not the other way around.

Talk soon,

Kevin

P.S. If you're making any of these mistakes and need help building a proper outbound system that actually reaches inboxes, book a strategy call with me.