7 Email & SMS Mistakes That Kill Your Results
- 7 Email & SMS Mistakes That Kill Your Results
- Mistake 1: Buying or Scraping Lists Instead of Earning Opt-Ins
- Mistake 2: Ignoring Deliverability Until It's Already Broken
- Mistake 3: Treating SMS Like Email
- Mistake 4: No Segmentation, Batch-and-Blast Forever
- Mistake 5: Automations Set Once and Never Revisited
- Mistake 6: Weak or Missing Compliance Practices
- Mistake 7: Only Measuring Opens and Clicks, Never Revenue
Most underperforming email and SMS programs aren’t failing because of bad copy — they’re failing because of structural mistakes made months or years earlier that nobody’s gone back to fix. The seven mistakes below are the ones we see most consistently when auditing an existing program, roughly in order of how much damage they do.
If your program feels stuck despite reasonable effort, work through this list against your own setup before touching another subject line.
Mistake 1: Buying or Scraping Lists Instead of Earning Opt-Ins
This is the mistake that poisons everything downstream. A purchased or scraped list has never expressed interest in your brand, which means open rates crater, spam complaints spike, and your sender reputation takes damage that follows your domain for months. Mailbox providers track complaint rates at the domain level — one bad send to a purchased list can hurt deliverability for every legitimate campaign that follows it.
The fix is simple in principle and hard in practice: build your list exclusively through genuine opt-in, even if it means starting smaller and growing slower. A list of a few hundred people who actually want to hear from you will outperform tens of thousands of cold, purchased contacts on every metric that matters to your business.
Mistake 2: Ignoring Deliverability Until It's Already Broken
Deliverability is invisible until it fails, which is exactly why it gets ignored. Businesses set up their ESP, skip proper SPF/DKIM/DMARC configuration, never monitor bounce or complaint rates, and only notice a problem when open rates have already been quietly declining for months.
Deliverability isn’t a one-time setup task — it’s an ongoing discipline. Authenticate your domain before your first send, warm up new sending infrastructure gradually, monitor bounce and complaint rates as standing metrics rather than only checking after a bad campaign, and suppress hard bounces and chronically unengaged addresses on a recurring schedule. Reputation is far easier to protect than to rebuild once it’s damaged.
Mistake 3: Treating SMS Like Email
SMS and email are fundamentally different channels with different reader expectations, and treating them the same is one of the most common — and most damaging — mistakes newer programs make. Sending SMS at email frequency, writing SMS copy with the same length and structure as an email, or skipping brand identification because “they’ll know it’s us” all misjudge what makes SMS work.
SMS readers expect brevity, immediacy, and restraint in frequency. A subscriber who tolerates several emails a week may opt out after just a couple of texts in the same period, because the channel itself carries a higher expectation of relevance and urgency. Every SMS should identify your brand clearly, get to the point immediately, and be reserved for messages genuinely worth an instant interruption — order updates, time-sensitive offers, appointment reminders — not routine content that belongs in email instead.
Mistake 4: No Segmentation, Batch-and-Blast Forever
Sending the same message to your entire list regardless of behavior, purchase history, or engagement level is one of the fastest ways to plateau. Highly engaged subscribers get buried in irrelevant content, at-risk subscribers get pushed further away by messaging that doesn’t reflect their waning interest, and everyone in between gets a generic experience that doesn’t build any real relationship.
Segmentation doesn’t need to be sophisticated to start delivering value — even splitting your list into “engaged” and “everyone else,” and adjusting frequency and content accordingly, produces a meaningful lift over pure batch-and-blast sending. Add behavioral and purchase-based segments as your data matures.
Mistake 5: Automations Set Once and Never Revisited
Automated flows are the highest-leverage asset in most programs, which makes it especially costly when they’re built once and forgotten. Product lines change, offers expire, seasonal relevance shifts, and a welcome series or abandoned-cart flow written months or years ago can quietly reference outdated promotions or miss opportunities that didn’t exist when it was built.
Put automations on the same recurring review cycle as your active campaign calendar. At minimum, audit your core flows — welcome, abandoned cart, post-purchase, win-back — every quarter, checking both the content and the underlying logic (timing, exit conditions, segment eligibility) against how your business actually operates today.
Mistake 6: Weak or Missing Compliance Practices
Skipping proper consent documentation, missing unsubscribe mechanisms, ignoring STOP-keyword processing for SMS, or failing to disclose message frequency at opt-in are all compliance gaps that carry real legal and financial exposure — not just theoretical risk. Regulators and carriers both enforce these rules, and SMS carriers in particular can filter or block a sending number entirely for repeated violations, cutting off the channel regardless of how good your content is.
Compliance isn’t a one-time legal review — it needs to be built into your platform configuration and checked whenever you change platforms, add a new opt-in point, or expand into a new market with different rules. Treat it as infrastructure, not paperwork.
Mistake 7: Only Measuring Opens and Clicks, Never Revenue
Open rate and click rate are useful diagnostic metrics, but they’re not business outcomes. A campaign with a strong open rate that generates no revenue isn’t a success, and a program that only ever reports on these top-of-funnel numbers can look healthy while actually declining in the metric that matters most.
Track revenue per recipient at the campaign and automation level, and review it alongside list growth net of unsubscribes. This reframing changes decisions — a campaign with a mediocre open rate but strong revenue per recipient might be worth repeating more often than a high-open, low-revenue send that looks better on a surface-level report.
Frequently Asked Questions
What's the single most damaging email and SMS mistake?
Buying or scraping a list. It undermines deliverability, wastes budget on people who never wanted to hear from you, and can damage your sender reputation for every future campaign, since mailbox providers track reputation at the domain level.
How do I know if my automations need updating?
If a flow hasn't been reviewed in the last few months, or if your product line, offers, or business model have changed since it was built, it's overdue for an audit. Check both the content and the underlying trigger logic, not just the copy.
Why is over-texting worse than over-emailing?
SMS carries a higher expectation of relevance and urgency because it interrupts the reader directly, so tolerance for frequency is much lower than email. Over-texting drives opt-outs and carrier complaints faster than over-emailing typically drives unsubscribes.
Can a single bad campaign really hurt my deliverability long-term?
A single send to a poor-quality list can generate enough bounces and spam complaints to damage sender reputation at the domain level, and that damage can affect subsequent legitimate campaigns for weeks or months while you rebuild trust with mailbox providers.
Is it worth fixing an underperforming program, or should I start over?
In almost every case, it's worth auditing and fixing the existing program rather than starting from scratch — your list, however imperfect, represents real relationships and history that a fresh start would throw away. Work through the mistakes above systematically before considering a full rebuild.
Terry has 30+ years in software and SEO. He’s the founder of Salterra Digital Services and SEO Spring Training, host of the Roundtable SEO Mastermind, and lead instructor at SEO University — teaching the exact tactics his team uses on client work.
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