Stop Tracking Open Rates. Your Deliverability Will Thank You.
Tracking open rates could be sending your emails to spam. Learn why the metric is unreliable and what to measure instead.
Akash Bhadange • 3/24/2026 • how to guide
Akash Bhadange • 12/30/2025 • how to guide
You already know which emails are the problem.
The welcome email that 30% of new users never see. The password reset buried under Gmail's Promotions tab. The product update your customers swear they never received.
Most frustrating part of email is, these problems are very hard to find and figure out. You might think all of this is happening because of the email content. But many times it's a technical or behavioral mistake that spam filters have been trained to catch and most of them are completely fixable once you know what to look for.
I run AutoSend, an email service that helps you send transactional and marketing emails. I have seen many of our customers making these mistakes constantly.
A customer with 100k sending volume reached out to us because none of their campaigns were working out. I check their setup and spot it immediately: they're sending from noreply@, and they just blasted 17,000 emails from a three-week-old domain.
These aren't edge cases. They're the most common reasons emails land in spam.
Before reading the full guide, check these first. If any of these are true, fix them before anything else:
SPF record missing or misconfigured
DKIM not enabled on your sending domain
DMARC policy not set
Sending from noreply@ or no-reply@
Domain is less than 60 days old and you're sending volume
No unsubscribe link in marketing emails
Complaint rate above 0.1%
Bounce rate above 3%
If you checked two or more of these, start there. Those are your biggest deliverability killers.
These will get you blacklisted or blocked fast. If you're making any of these, everything else is secondary.
Why it causes spam: Inbox providers treat unauthenticated emails as impersonation attempts, with no way to verify you are who you claim to be.
Inbox providers automatically flag unauthenticated emails as potential impersonation attempts. Without these three protocols configured, your emails have no way to prove they're legitimately from you.
How to fix it: Set up all three in your DNS records. Verify they're working with a tool like MXToolbox or mail-tester.com. If you're sending through AutoSend, we verify your DKIM during domain setup. You'll see a green check in your dashboard once it's confirmed.
For a full walkthrough: How SPF, DKIM, and DMARC Work Together
You might want to send OTPs and transactional email via no-reply email ids as this is a standard practice. But, if your domain is new and you do not have much sending reputation, try to avoid it. These addresses signal to spam filters that you don't want engagement, which is exactly what spam does. Inbox providers prioritize emails that look like two-way communication.
How to fix it: Use a real address. hello@, support@, team@, or your own name. If you need to suppress replies for a specific email type, use a filter on the inbox instead of a dead-address sender.
But honestly, it's the best if you receive replies to your emails. That signals you are a legitimate sender and ISPs will start trusting you.
This one is a BIG NO! This violates CAN-SPAM and GDPR. When users get emails they already unsubscribed from, they report spam immediately. Your domain reputation tanks fast and the damage is hard to recover from.
How to fix it: Never delete suppression lists. They're not a list of failures. They're a record of people who have the legal right not to hear from you. Honor them permanently. If you want to re-engage, run a proper win-back campaign to people who simply stopped opening, not people who explicitly opted out.
CAN-SPAM requires a working unsubscribe mechanism and a physical postal address in every commercial email. No exceptions.
How to fix it: Every marketing email needs a one-click unsubscribe and your business address in the footer. Transactional emails do not strictly need unsubscribe link. You can mention them as system-notifications. But if the email has any promotional element, you need it.
These won't get you blacklisted overnight, but they cause a steady reputation decline. If you're seeing a gradual drop in deliverability or inconsistent inbox placement, one of these is likely the cause.
A new domain has zero sending history. When you immediately send thousands of emails from it, you look exactly like a spam operation — because that's also what spam operations do.
How to fix it: Warm up your domain over 2–4 weeks. Start with 50–100 emails per day to your most engaged contacts. Gradually increase volume. This builds the reputation signal that inbox providers need before they'll trust you at scale.
Full guide: How to Warm Up a New Email Domain
A new domain plus unsolicited emails is a double red flag. Even legitimate cold outreach needs a warmed domain first.
How to fix it: Before you start any cold outreach, spend at least two weeks warming your domain with transactional or engaged-subscriber email. Keep cold outreach volume small and separate it from your main sending domain if possible.
Spammers use URL shorteners to hide malicious destinations, so filters treat them as a red flag regardless of who's using them. Also, it is hard for the users to see the actual URL and trust your email. So while you are sending your email, think of every possible way to increase trust of your users. Show all your links, let them see what they are clicking on and committing to. This engagement with your email is going to help you build trust.
How to fix it: Use full destination URLs. If you need click tracking, use a custom domain short link that's authenticated and associated with your brand.
Note: If you're using AutoSend's click tracking, we handle this automatically using our branded tracking domain, so your links stay clean.
These lists contain spam traps, inactive addresses, and people who never gave any permission to hear from you. Your complaint rate spikes immediately, and that damage follows your domain.
How to fix it: Only email people who explicitly opted in. No shortcuts here. If you're trying to build a list fast, focus on owned channels — product signups, content opt-ins, referrals.
When your From address is @yourcompany.com but your Reply-To is @anotherdomain.com, it looks like a phishing setup, because that's how phishing emails are often structured.
How to fix it: Keep both addresses on the same authenticated domain. If you genuinely need replies to go somewhere else, make sure both domains are authenticated and the difference is explained clearly to recipients.
This section is specifically for developers sending transactional email programmatically including password resets, receipts, notifications, onboarding sequences. The mistakes here are different from marketing email issues and they're often invisible until something breaks badly.
If your application keeps retrying sends to addresses that hard bounced, your reputation degrades quickly. Most developers don't realize their email provider is silently logging bounces while their code keeps firing.
How to fix it: Set up webhook listeners for bounce and complaint events. Hard bounces should be suppressed immediately. Soft bounces should be retried a limited number of times before suppression.
In AutoSend, bounce and complaint webhooks are available under Settings > Webhooks.
Mixing your transactional email (password resets, receipts) with your marketing email (campaigns, newsletters) on one domain is risky. A spam complaint from a marketing email can affect deliverability for your transactional email.
How to fix it: Use a subdomain for transactional email maybe mail.yourdomain.com or notifications.yourdomain.com. This separates the reputation so a marketing issue doesn't interrupt your product's critical email flow.
Most developers check delivery rates but not complaint rates. Gmail's Postmaster Tools and inbox providers surface complaint data that your sending platform alone won't show you.
How to fix it: Set up [Google Postmaster Tools](https://postmaster.google.com) for your sending domain. Your complaint rate should stay below 0.1%. Above 0.3% and you're in danger of bulk filtering. AutoSend's Email Activity dashboard also surfaces complaint events in real time.
Soft bounces (mailbox full, temporary server error) are often overlooked because emails eventually get through. But a pattern of soft bounces to the same address signals list hygiene problems.
How to fix it: Track soft bounce patterns. If an address soft bounces three or more times in a row, treat it as a hard bounce and suppress it.
These increase your spam score incrementally. None of them will tank you alone, but in combination, especially with one of the above, they push you over the threshold.
Emails that are mostly images with little text look like advertisements to spam filters, and they have nothing to analyze for content signals. They're also bad for accessibility and dark mode.
How to fix it: Keep a 60/40 or 70/30 text-to-image ratio. Always include a plain text version of every email. If you're sending HTML, make sure the copy carries the message even without images loading.
Each link adds to your spam score, and 10+ links in a single email looks like a link farm. Spam filters count them.
How to fix it: Keep it to 3–5 links maximum. Every link should have a clear purpose. If you're finding yourself adding more, it's a sign the email is trying to do too many things at once.
"URGENT!!!", "You've been selected", "Re:" with no prior thread, these trigger filters and erode recipient trust even when they don't land in spam. Don't create urgency for people to act on something.
How to fix it: Write subject lines that accurately describe what's inside. If the email is worth sending, the subject line shouldn't need to manufacture urgency. Specificity beats clickbait every time.
"Dear Friend", "Hello there", "Hey valued customer", generic greetings tell spam filters (and recipients) that you don't actually know who you're writing to.
How to fix it: Use first name personalization. If you don't have their name, consider whether you should be emailing them at all.
WRITING IN ALL CAPS or piling on exclamation marks triggers filters and looks unprofessional. Spam has trained both algorithms and people to associate these patterns with low-quality senders.
How to fix it: Write like a human having a normal conversation. If your email needs ALL CAPS to feel urgent, the problem is the message, not the formatting.
You don't need to fix all 18 at once. Work through them in order of severity:
1. Critical first: Authentication (SPF, DKIM, DMARC), list hygiene, legal compliance
2. Then high-impact: Domain warmup, bounce handling, list quality
3. Then developer-specific: Webhook setup, subdomain separation, monitoring
4. Medium last: Formatting, subject lines, content patterns
Most of the critical and high-impact fixes are one-time setups. Do them once, do them right, and they stop being a problem.
The medium-impact ones are habits. They get easier once you've internalized what spam filters are actually looking for: signs that a real person sent this to another real person who wanted to receive it.
The bottom line for emails is, be genuine with your users and you will get more value from everyone. Email is a 40-year-old technology, so in whatever way you try to hack it, it will catch you and that will impact your business directly. So best way is to go slowly and genuinely.
If you're dealing with a specific deliverability issue, complaint rate spikes, sudden inbox placement drops, or setting up a new sending domain from scratch, I'm happy to take a look.
AutoSend gives you full visibility into your email activity, bounce and complaint webhooks, domain warmup and a clean API that handles a lot of these best practices by default. If you are looking to send transactional, marketing or automation emails, you should check this out.
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