Don't get your email deliverability caught in the web of spam filters

5 Modern Spam Triggers to Avoid with Cold Email

Don't get your email deliverability caught in the web of spam filters

The best email messages out there can’t make an impact if they never end up in the inbox of their target recipients.

Maintaining cold email deliverability used to be easy to achieve and it boiled down into simple best practices that companies could quickly learn.

Today it’s a pitched battle against Internet Service Providers (ISPs) and spam filters that use advanced algorithms and artificial intelligence to spot spam email by analyzing billions of emails in real-time.

In a short period of time, this level of sophistication has made it harder than ever to set up, ramp-up, and sustain cold email delivery & deliverability without running into issues.

Are you successfully delivering emails or getting caught by spam filters and blacklists? To help maximize cold email deliverability, be aware of these 5 common spam triggers.

Trigger 1: Lacking Email Server Configuration

Many companies aren’t careful enough with how they should configure their infrastructure for a consistent, sustainable cold email campaign.

Even after setting up the basics like SPF and DKIM, it’s beneficial in today’s world to go a step further with some additional configuration steps.

For example, setting up Domain-based Message Authentication, Reporting, and Conformance (DMARC) for your domain helps protect your email from cybercrimes while also improving your reputation among ISPs and ESP.

Another example is creating a domain for your cold email campaign with a separate IP so your email prospecting doesn’t impact communications with team and customers.

Trigger 2: Having Too Many Email Links or Images

Every email you send gets scrutinized by spam filters to determine how normal it looks compared to the billions of other senders.

Too many links, images, or having suspicious linking practices can trigger spam filters and increase the risk your emails get marked as spammy.

To ensure your links and images don’t impact deliverability, try removing them from the first few emails sent to a new recipient.

In addition, be conservative in the number of links and images you use to prevent one of your templates from disrupting cold email deliverability for the entire campaign.

Trigger 3: Using Spammy Keywords or Messaging Tactics

One method spam filters have consistently used to remove spammy emails with success is the analysis of email content.

Specific words, phrases, or HTML formatting can be dead giveaways for spam filters because they have billions of emails informing their filtering methods.

Even if they don’t flag you, most spam filters will handle and treat spammy messaging differently.

To avoid this scrutiny, you need to be cautious of how you write your email content and stay aware of how specific messaging can impact your deliverability.

Trigger 4: Low Email Engagement Metrics

While many companies pay attention to list hygiene, most fail to understand how their sender reputation gets impacted by how recipients react to your emails.

Spam filters scrutinize every interaction your recipients take with your emails to decide whether you’re a reputable sender or a potential email spammer.

Recipient behaviors like not opening emails, spam complaints, or unsubscribes can damage your reputation and make it harder for you to cold email over time.

To protect your deliverability, you need to be aware of how email engagement impacts your sender reputation and be methodical in how you engage with recipients.

Trigger 5: Email Sending Volume & Frequency

The most common trigger blocking marketers that use cold email is the volume and sending patterns of your email outreach.

Email sending volume is like a really tough game with levels: the larger your sending volume, the more scrutiny you’ll get from spam filters and more challenges you’ll have.

Especially when starting out with cold email, you should be careful in how many emails you send every day and increase volume by ramping up slowly over time.

To maximize your success with cold email, be constantly aware of how your sending volume impacts your sender reputation and email deliverability.


Companies often overlook their deliverability issues and tend to resolve them temporarily with new technology, new sending services, or new email accounts.

However, these fixes can only take you so far. Once your IPs become blacklisted or targeted by spam filters, finding a solution becomes a major, time-consuming problem.

Rather than focusing on temporary solutions until deliverability hits a breaking point, make changes early on to help prevent more severe sending issues down the road.

Being proactive about deliverability improvements helps make sending emails easier in the long run while also enabling you to do higher volumes of outreach for longer.

[Generating outbound leads? Check out our new free video series the Cold Email Playbook to get insights and content from 7 cold email experts]