This guide covers what you need to know to get the best results from your Zap Contact campaigns. The short version: we handle the technical infrastructure, you focus on writing good emails and sending at a smart pace. Here's how to do both well.
Before we get into what you need to do, here's what you don't need to worry about. All of this is set up and managed on your behalf when you sign up:
Dedicated sending domain — We register a separate domain for your email campaigns and configure all the DNS records (SPF, DKIM, DMARC) so your emails are properly authenticated. This protects your main business domain and gives you a clean reputation to build on.
Email verification — Every email is checked in real-time before it's sent. Invalid or risky addresses are skipped automatically, which keeps your bounce rate low (typically under 2%) without any effort on your part. Emails that do bounce are permanently flagged so they're never sent to again.
Unsubscribe compliance — Every email includes a working unsubscribe link. When someone unsubscribes, they're immediately and permanently removed from future sends. This keeps you in full CAN-SPAM compliance automatically.
That's the infrastructure. Now here's what makes the difference on your end.
Even with perfect infrastructure, a bad email will land in spam. Here's what inbox providers are looking for:
Send Text NOT HTML. HTML Templates are red flags for spam filters. It doesn't matter how good they look if they don't make it to the inbox. The goal of the email is to START the sales process, not close it. Let you website and phone do the closing. Text is how people normally communicate by email so it is presumptively non-commercial.
Subject lines matter most. Avoid ALL CAPS, excessive punctuation (!!!), and clickbait phrases like "Act Now" or "Limited Time Offer." Write subject lines that sound like they came from a real person, not a marketing machine. "Quick question about your [city] practice" will always outperform "AMAZING OPPORTUNITY FOR DOCTORS!!!"
Keep it short and personal. Cold email works best when it reads like a one-to-one message, not a newsletter. A few short paragraphs with a clear call to action will outperform a long, image-heavy marketing blast every time. Use personalization fields (like {{first_name}} and {{city}}) to make each email feel relevant to the recipient.
Avoid common spam triggers. URL shorteners (like bit.ly) are heavily associated with spam — use full URLs instead. Don't attach files to cold emails. Go easy on images; a text-heavy email with one image is fine, but an email that's mostly images with little text looks like spam to inbox providers. And don't use a free email address (gmail, yahoo) as your "from" address — always use your dedicated sending domain.
Test before you send. Use mail-tester.com to check your email's spam score before sending to your full list. Create a test contact using the temporary email address the site provides, send your draft to that address, then check your score. Aim for 8/10 or higher. It takes two minutes and can save an entire campaign.
Use Drip Mode to the free email domains (gmail, yahoo, AOL, hotmail, etc) for anything over a few hundred emails. Sending 10,000 emails simultaneously tells Gmail and Yahoo that you're a bulk sender, and they'll throttle or spam you accordingly. Drip Mode spaces your sends out over hours or days, which looks much more natural and dramatically improves inbox placement.
Don't email the same people too often. For cold email, sending to the same contacts more than once a week is too aggressive and will generate spam complaints. Every two weeks is a good rhythm. Once a month is the minimum if you want to stay on people's radar. Find your sweet spot and be consistent.
Don't send too infrequently either. If you only send once every few months, inbox providers forget your reputation and you're essentially starting the warm-up process over. Regular, moderate sending builds and maintains your domain's credibility.
Stop sending to people who never engage. If someone hasn't opened any of your last several campaigns, continuing to email them hurts your deliverability. Inbox providers track engagement — when a high percentage of your recipients ignore your emails, it signals that your messages aren't wanted, and more of them get routed to spam.
It feels counterintuitive to shrink your list, but a smaller, engaged list will always outperform a large, unresponsive one. Use your campaign reports to identify contacts who have never opened or clicked, and stop including them in future sends. Focus your effort (and credits) on the people who are actually reading your emails.
Let unsubscribes happen. It's better for someone to unsubscribe than to mark your email as spam. The unsubscribe removes one contact; a spam complaint damages your domain's reputation for every future email you send. Zap Contact makes unsubscribing easy and immediate, which actually protects your deliverability.
After each campaign, check your reports in the Zap App. Here's what to watch:
Bounce rate under 2% — The email verification handles most of this, but keep an eye on it. If you see bounces creeping up, contact me and we'll investigate.
Spam complaint rate under 0.1% — If more than 1 in 1,000 recipients are marking your email as spam, something needs to change: your content, your sending frequency, or your audience targeting. This is the most important number to watch.
Open rates above 15–20% — For cold email, 15–20% opens is solid. If you're below 10%, your emails are likely hitting spam or your subject lines need work. If you're above 25%, you're doing great — keep doing what you're doing.
For advanced monitoring: Google Postmaster Tools lets you see exactly how Google rates your sending domain's reputation, spam rate, and authentication status. It takes a few minutes to set up (you add a DNS record to your sending domain) and the data is invaluable for high-volume senders. Ask me if you'd like help setting this up.
| Do | Don't |
| Use Drip Mode for large sends to the free email domains | Blast your entire list at once |
| Write short, personal emails | Send image-heavy marketing blasts |
| Test with mail-tester.com first | Use URL shorteners (bit.ly, etc.) |
| Send every 1–2 weeks | Email the same contacts daily |
| Be patient during warm-up | Send 10K emails in week one |
| Stop sending to unengaged contacts | Keep emailing people who never open |
| Use personalization fields | Use ALL CAPS or excessive punctuation |
Mail-Tester.com — Test how "spammy" your email looks before sending. Free, takes two minutes.
MXToolbox Email Health — Check your sending domain for blacklisting, missing records, or configuration issues.
Google Postmaster Tools — Monitor how Google rates your domain reputation, spam rate, and authentication. Best for high-volume senders.
Questions? This guide covers the fundamentals, but every campaign is different. Reach out at support@zapcontact.com or call/text 850-279-5420 and I'll help you put together a sending strategy that fits your list and your goals.
