How To Stay Out Of Spam

Email providers use hundreds of signals to decide where your email goes. But most spam placement comes down to a handful of factors that you can control.

• Use a dedicated sending domain — never your primary company domain
• Configure SPF, DKIM, and DMARC — all three, not just one or two
• Warm up the domain for 2–4 weeks before sending cold email
• Keep warmup running in the background during campaigns
• Verify your domain is not on any blacklists (check MXToolbox regularly)

Volume Management

Spam filters flag sudden volume changes. A domain that sends 10 emails yesterday and 200 today looks suspicious. Ramp gradually: start at 20–30 per day and increase by 5–10 per day over several weeks.

Consistency

Send consistently. Irregular patterns — a big batch one week, nothing the next — confuse reputation algorithms. Aim for steady, predictable daily volume.

Timing

Spread sends throughout the day rather than firing off a batch in one burst. Most cold email tools handle this automatically with sending windows.

Spam filters analyze your email content for red flags. Here is what to do and what to avoid.

Content Best Practices

• Write plain text emails — no HTML templates, no images, no designed layouts
• Keep emails under 150 words
• Use 0–1 links per email (multiple links are a spam signal)
• Do not include attachments in cold emails
• Personalize the opening line with something specific about the recipient
• Use a clear, specific subject line (avoid ALL CAPS and exclamation marks)

Content to Avoid

• Spam trigger phrases: 'free', 'act now', 'limited time', 'congratulations'
• Excessive punctuation or capitalization!!!
• Multiple hyperlinks
• Large images or image-heavy emails
• HTML-heavy designed emails
• Generic greeting: 'Dear Sir/Madam', 'To whom it may concern'

Your list quality is one of the strongest deliverability signals. Sending to bad addresses hurts you in multiple ways: high bounces damage reputation, low engagement signals irrelevance, and spam complaints from irrelevant emails accumulate quickly.

• Verify every email address before adding it to your list
• Remove hard bounces immediately after every send
• Remove contacts who have never engaged after 3+ emails
• Target people who actually have the problem you solve
• Re-verify your list every 30–60 days
• Keep your list under 500 well-researched contacts per campaign

After your email reaches the inbox, what the recipient does with it influences your future deliverability. Positive engagement trains spam filters to trust you. Negative engagement trains them to block you.

This is why personalization matters so much. Relevant, targeted emails earn opens and replies. Generic emails earn deletes and spam reports.

Do not wait for a crisis to check your deliverability. Build monitoring into your routine.

• Check Google Postmaster Tools weekly
• Monitor bounce rates after every campaign
• Track open rates as a deliverability proxy
• Set alerts for bounce rates above 3% or open rates below 30%
• Check blacklists monthly at MXToolbox
• Review DMARC reports for authentication failures

If you notice a drop in open rates or an increase in bounces, pause sending and diagnose before continuing. It is always better to lose a few days of sending than to permanently damage your domain reputation.