How can Businesses Avoid Spam Filters and Increase Email Open Rates?

Writing a strong outreach email takes thought, strategy, and a lot of heart. Sales reps pour their time into crafting subject lines that spark curiosity, messages that show real value, and follow-ups that feel human. So when open rates stay low and replies stall, it can feel like something important is missing.

Here’s the reality: According to Mailchimp, the average email open rate across industries is just 21.33%—and that number drops even more when deliverability issues get in the way. If your emails aren’t reaching inboxes, they aren’t reaching prospects. That means fewer conversations, fewer booked meetings, and slower momentum.

However, a few smart strategies can help land your emails directly in your prospects’ primary inbox, right where they’re most likely to see and open them. With tools like Outplay, it’s easier than ever to stay ahead of spam filters, personalize at scale, and maintain a strong sender reputation.

Why Emails Land in Spam

Even the most thoughtful emails need a little behind-the-scenes support to reach the inbox. Let’s take a look at what can influence their journey:

Use of promotional language : Words like “Buy now,” “FREE,” or “Act fast” can come across as overly promotional. Keeping your language natural, value-focused, and authentic helps your message sound more like a conversation than a sales pitch.
Outdated contact lists: Reaching out to people who haven’t interacted in a while, or using lists that haven’t been updated, can reduce your sender reputation. Clean, engaged lists are a sign of healthy outreach.
Domain reputation matters: Email providers look at your sending history, high bounce rates or low engagement can signal low trust. A solid reputation is built by consistently sending valuable content to interested recipients.
How filters decide: ISPs and email clients use advanced algorithms that assess your emails based on sender behavior, email structure, and recipient engagement. The more positive signals, the more likely your emails reach inboxes.
The role of authentication: Protocols like SPF, DKIM, and DMARC verify that your email is really coming from you. It’s like showing your ID at the door, ensuring your message is welcomed in.

How to Build and Maintain a High-quality Email List

A strong, engaged list is the heart of every successful email campaign. When your contacts genuinely want to hear from you, great deliverability naturally follows. Here’s how to build that kind of list:

Choose relationships over reach
Purchased lists might look impressive in size, but they don’t always lead to meaningful conversations. It's better to connect with people who’ve shown genuine interest in your brand.

For example, someone who visited your pricing page or signed up for a product demo is far more likely to engage than a stranger pulled from a third-party database.

Invite with intention
When people opt in through lead magnets like helpful guides, newsletters, or webinar signups, they’re saying, “I want to hear more.” That’s a beautiful place to start a relationship.

A quick-start checklist for sales teams or an on-demand webinar replay can be great entry points to collect emails authentically.

Keep the list fresh
Every list needs a little spring cleaning now and then. Removing hard bounces, duplicate contacts, and folks who haven’t interacted in a while helps protect your sender reputation.

For example, if someone hasn’t opened an email in 90 days, it may be time to pause communication or re-engage with a targeted campaign.

Outplay takes care of this with ease. Its smart engagement tracking automatically flags and removes inactive contacts, so your team always focuses on the leads most likely to respond and convert.

Personalization is the Answer

When it comes to email outreach, a little thoughtfulness goes a long way. People respond to messages that feel like they were written for them, not just at them. Here's how to make every email count:

Add those personal touches
Using the recipient’s name, company, or recent news shows you're paying attention. For instance, mentioning their recent product launch or a new funding round makes your email feel timely and relevant, like a message from a colleague, not a mass blast.
Show you understand their world
Customizing your message to a specific pain point creates instant connection. If you know a company is hiring rapidly, you might say, “I noticed your team is growing, here’s how we help new sales reps ramp faster.” This kind of empathy makes your message feel more like help, less like a pitch.
Write like a human, not a script
Templates are helpful, but when every sentence feels stiff or overly formal, it creates distance. Instead, write how you’d speak. For example, “Thought this might help as you prepare for Q2” feels natural, friendly, and easy to respond to.

With AI-powered personalization and dynamic fields, Outplay helps you craft thoughtful messages at scale, so every rep can stay human, even while automating parts of the process.

Optimize Subject Lines and Preview Text

Subject lines and preview text are like the opening scene of your favorite movie—they set the tone and pull the reader in. A well-written opener can spark interest, curiosity, and clicks. Let’s make yours shine:

Keep it short and benefit-focused
Your subject line should be like a friendly nudge, and not a billboard. Short, clear lines like “Save 2 hours a week on outreach” or “New strategy for hitting quota faster” promise value without sounding pushy. Aim for 5–7 words that speak to your reader’s goals.
Spark curiosity (gently)
A little intrigue can go a long way. Subject lines like “One small tweak changed our reply rate” or “You might like this approach” encourage opens without giving everything away. The idea is to get them curious enough to click, without relying on tricks.
Test to learn what works
What works for one audience may surprise another. A/B testing subject lines lets you try out different tones, like formal vs. casual, or value-focused vs. curiosity-driven. Over time, patterns emerge, helping you fine-tune your outreach approach.
Choose your words wisely
Some phrases, while well-intended, can sound too promotional. Instead of “FREE demo,” try “Quick walkthrough—on us.” Rather than “BUY NOW,” something like “Is this worth a look?” feels lighter and more natural.

Outplay’s A/B testing feature makes it easy to test multiple subject lines in the same campaign, helping your team figure out what resonates, without slowing them down.

Master the Technical Setup

Great emails deserve a smooth ride to the inbox. A little technical TLC in the background can go a long way in supporting strong deliverability and helping your emails land right where they should.

Start with a warm-up plan
Just like easing into a new workout, your domain needs time to build strength. Begin by sending small batches of emails and gradually increasing volume over a few weeks. For example, start with 20 emails a day and slowly ramp to your target number. This tells inbox providers you're consistent, trustworthy, and in control.
Stick to smart sending limits
Staying within healthy daily limits helps keep your domain reputation in great shape. Instead of sending 1,000 emails in a single blast, space them out across your team or time zones. This makes your outreach feel more organic—and inboxes appreciate that.
Use a custom tracking domain
Custom domains personalize your email links and make tracking look cleaner and more credible. For instance, instead of a shared tracking link like “email-tracker.com,” use something branded like “go.yourcompany.com.” It builds trust while keeping your analytics sharp.
Set up SPF, DKIM, and DMARC records
These three email authentication protocols act like your digital credentials. They confirm that you’re a legitimate sender. When set up correctly, they tell ISPs, “This sender checks out.” Think of it as putting a friendly stamp of approval on every message.

Outplay simplifies the entire technical setup, from domain warm-up to SPF/DKIM/DMARC validation, so your team can focus on sending great emails, knowing the backend is handled with care.

Consistency and Timing Matter

Crafting the right message is essential, but delivering it at the perfect moment? That’s when it truly becomes powerful. When your emails arrive consistently and at the right time, you build trust and improve engagement.

Timing is everything
People check their inboxes at different times, but some windows just work better. Sending outreach mid-morning on a weekday, say, around 10 AM local time, tends to see higher open rates. For example, a prospect starting their day with a fresh cup of coffee is far more likely to open your message than one buried in end-of-day clutter.
Find a rhythm that feels natural
Reaching out too frequently can feel overwhelming, while long gaps might cause your message to get lost. A steady cadence, like one follow-up every 3–5 business days, keeps your name top-of-mind without pushing too hard. It’s like checking in, not checking off.

Outplay’s send time optimization feature helps you schedule emails when prospects are most likely to open and engage, so your message arrives exactly when it has the best chance to land.

Monitor Deliverability and Iterate

Once your emails are out in the world, the next step is to listen to what they’re telling you. Monitoring performance gives you clues about what’s working, and where you might want to adjust.

Watch key metrics closely
Open rates, click-through rates, and reply rates give you a quick snapshot of how your emails are performing. For example, if your open rate dips below 20%, it might be time to revisit your subject lines or sending times.
Pay attention to bounce and complaint rates
High bounce rates can signal old or incorrect email addresses, while complaint rates (when recipients mark your emails as spam) may indicate it’s time to rework your message tone or frequency. Keeping these numbers low protects your sender reputation and keeps your emails on track.
Test, tweak, and improve
Email outreach is a living process. A/B test different subject lines, calls to action, or sending days. Try something new, see what lands, and build from there, small shifts can bring big improvements over time.

With real-time deliverability and engagement reports, Outplay helps you stay tuned in to what’s working and where to improve allowing your team to adjust faster and connect more effectively.

Outplay’s Built-in Email Deliverability Features

Keeping your outreach strong starts with the right tools. Outplay is built to make great email deliverability simple, even for busy sales teams with full plates.

Here’s what’s working quietly in the background so your reps can shine out front:

Domain warm-up: Gradually builds your sender reputation so your emails reach inboxes more consistently.
Email validation: Checks addresses before you hit send—no time wasted on typos or inactive contacts.
Inbox placement testing: Gives you a sneak peek at where your email will land—Primary tab, Promotions, or Spam—so you can course-correct ahead of time.
Spam score prediction: Flags risky words or formatting so you can fine-tune your message before hitting send.
AI-powered personalization: Helps your team craft thoughtful, tailored emails at scale, because connection matters.
Engagement tracking: Keeps you informed about opens, clicks, and replies, so you always know what’s working.

With these features working together, your emails are set up for success from the first draft to the final send.

Make Inbox Placement Your New Standard

Deliverability doesn’t have to feel complicated. When you pair smart strategy with the right tools, email becomes more than a channel; it becomes a reliable path to real conversations and a better pipeline.

Outplay makes it easy to stay consistent, personal, and technically sound, so your emails show up exactly where they belong: in your prospects’ inboxes, ready to be opened.

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