If you’re sending emails for business—outreach, sales, newsletters, whatever—you already know getting into the inbox is half the battle. If your emails aren’t getting delivered, nothing else matters. This guide is for anyone using Sendtrumpet who wants to actually understand their deliverability numbers, cut through the noise, and do something about them.
Why deliverability isn’t just a “set it and forget it” thing
Most folks think deliverability is a technical checkbox—you set up SPF, DKIM, and call it a day. Truth is, those are just table stakes. Internet Service Providers (ISPs) are constantly shifting the goalposts. What worked last year might land you in spam today.
If you’re sending cold outreach or any kind of bulk email, you have to keep an eye on your numbers. Otherwise, you’ll wake up one day to open rates that tanked for no obvious reason.
The metrics that actually matter (and the ones that don’t)
Before you drown in dashboards, here’s what you really need to track:
- Delivered rate: Percentage of emails that didn’t bounce. High deliverability doesn’t always mean high inbox placement, but low deliverability is always bad news.
- Bounce rate: Emails that were rejected. Hard bounces (invalid addresses) are worse than soft bounces (temporary errors).
- Spam complaint rate: How often recipients mark you as spam. Even one or two per thousand can hurt.
- Open rate: A rough proxy for inbox placement, but don’t obsess—Apple’s privacy changes and image blockers make this unreliable.
- Reply rate: For cold outreach, replies matter more than opens. Low replies can signal poor targeting or spam-folder placement.
Ignore: Vanity metrics like “delivered in X seconds,” or generic “engagement scores.” Focus on what you control and what impacts your actual business.
Step 1: Set up your foundation in Sendtrumpet
Before worrying about numbers, get your sending setup right. In Sendtrumpet, double-check these:
- Authenticate your domain: Use SPF, DKIM, and ideally DMARC. If you don’t, you’re asking to be flagged as spam. Sendtrumpet will walk you through DNS setup—don’t skip this.
- Warm up your sending domain: If this is a new domain or you haven’t sent many emails, start slow. Don’t blast out 500 emails on day one; ramp up gradually.
- Send from your own domain: Avoid free email addresses (like @gmail.com) for any serious campaigns.
- Separate cold and warm email domains: If you’re doing cold outreach, consider using a separate domain or subdomain so your main domain’s reputation isn’t at risk.
Pro tip: Use a tool to monitor blacklists, but don’t panic if you show up on obscure ones. Focus on deliverability, not chasing every list.
Step 2: Understand your Sendtrumpet dashboard
Sendtrumpet’s dashboard shows you the basics: delivered, bounced, opened, clicked, replied, and unsubscribed. But the interface isn’t magic—it’s just data. Here’s how to read it:
- Delivered: Should be 98%+ for good lists. If it’s lower, you’ve got list quality or technical issues.
- Bounced: Over 2% means your list is out of date or you’re scraping addresses. Clean your list.
- Spam complaints: Anything over 0.1% is a red flag. ISPs look at this closely.
- Open rate: Don’t panic if this drops. Look for trends, not single-day blips.
- Reply rate: For outbound, this is your North Star. If this tanks, your emails aren’t being seen or they suck (sorry, but true).
What to ignore: Click rates for plain-text emails (often wildly inaccurate), or “engagement” if you aren’t running nurturing campaigns.
Step 3: Interpreting the numbers—what’s really going on?
Don’t just stare at the dashboard. Here’s how to diagnose problems:
- Low delivered rate:
- Check for SPF/DKIM/DMARC errors in Sendtrumpet settings.
- Are you sending to a purchased list? Stop. ISPs hate this.
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Too much volume, too fast? Slow down—spread campaigns over days.
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High bounce rate:
- Clean your list. Use a tool to verify emails before uploading.
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Remove any addresses that bounced last time.
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High spam complaints:
- Your emails may look too “salesy” or generic.
- Your unsubscribe link is hard to find (make it easy).
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You’re sending too often. Reduce frequency.
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Open rate drops:
- Apple’s Mail Privacy Protection can inflate opens, but if you see a sudden drop, check if you’re landing in spam.
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Test with your own seed accounts across Gmail, Outlook, etc.
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Reply rate drops:
- Tweak your subject lines and copy.
- Double-check you’re targeting the right people—bad lists kill reply rates.
Pro tip: Don’t make a change every day. Watch for patterns over a week or two before you overhaul your approach.
Step 4: Actually improving deliverability (without the snake oil)
There’s no secret hack, but here’s what consistently works:
1. Keep your lists clean
- Use double opt-in for subscribers.
- Regularly remove inactive or bouncing addresses.
- Never buy or scrape email lists. Ever. These get you flagged, fast.
2. Send relevant, non-annoying content
- If it looks like spam, it’ll get treated like spam. Personalize your outreach, even a little.
- Avoid ALL CAPS SUBJECTS, lots of exclamation marks, and generic “Dear Sir or Madam” intros.
3. Mind your sending volume and schedule
- Spike your volume suddenly and you’ll get throttled or blocked. Ramp up, especially on new domains.
- Space out sends. Sendtrumpet lets you schedule batches—use it.
4. Make unsubscribing easy
- Hide the unsubscribe link, and people will hit spam instead. Make it obvious and painless.
5. Test, tweak, repeat
- Send test emails to yourself (use Gmail, Outlook, Yahoo, etc.) to see where you land.
- Change one variable at a time—subject, content, list—so you know what worked.
What to ignore: Anyone promising instant “inbox hacks” or “secret deliverability tools” that cost a fortune. Deliverability is about trust and good habits, not tricks.
Step 5: Advanced tactics (optional, but useful)
If you’ve nailed the basics and still want to go deeper:
- Use custom tracking domains: In Sendtrumpet, you can set up your own tracking links to avoid shared domain reputation issues.
- Rotate sending addresses: For high-volume cold outreach, rotate between several addresses (on separate domains) to spread risk.
- Monitor feedback loops: If you’re at real scale, sign up for ISP feedback loops to get notified when recipients mark you as spam.
Don’t get lost in the weeds here unless you’re sending thousands per day. Most small teams do fine just focusing on the basics.
What doesn’t work (despite what “experts” say)
- Changing up your sender name every week: ISPs see through this; it can make things worse.
- Using lots of images or fancy HTML in cold outreach: Triggers spam filters. Stick to simple, clean formatting.
- Overengineering your content: You’ll read advice about “avoiding trigger words”—but if your emails are relevant and wanted, you don’t need to obsess over every phrase.
Wrapping up: Don’t overthink it
Email deliverability isn’t magic, but it does take real effort. Start with a clean setup in Sendtrumpet, watch the numbers that matter, and make small, smart changes. Ignore the hype and keep it simple—monitor, tweak, and iterate. The best way to improve is to treat your recipients like actual people, not targets. If you do that, the numbers will usually follow.