Deliverability

Deliverability is the invisible variable in outbound. You can have perfect copy and a great list — if your emails land in spam, none of it matters. Most agencies treat deliverability as a setup task. We treat it as ongoing operations.

---

Why deliverability degrades

Sender reputation is dynamic. It’s built up over time and can be destroyed quickly. The main causes of deliverability problems:

• High bounce rates — Sending to invalid addresses tells providers your list is unverified
• Spam complaints — Even a few complaints per thousand sends can trigger filters
• Engagement drop — If your emails are never opened, providers learn to deprioritize them
• Sending spikes — Sudden volume increases look like compromised accounts
• Blacklisting — Landing on a major RBL affects deliverability across providers

We manage against all of these proactively.

---

Technical setup

Everything in the Infrastructure section is the foundation: SPF, DKIM, DMARC, custom tracking domains, and warmed mailboxes. If any of these are misconfigured, deliverability suffers regardless of what else we do.

We run a pre-send checklist before every new domain goes live:

• SPF record includes sending server
• DKIM selector is publishing and signing correctly
• DMARC is set to p=none monitoring with a reporting address
• No blacklist hits on MxToolbox or Spamhaus
• MX records are correctly pointed
• Warmup network is active and showing inbox placement > 90%

---

Sending behavior

Inbox providers have behavior detection. They can distinguish human-like sending from automation. We mimic natural patterns:

Volume ramp — Start low, increase gradually. A new inbox going from 0 to 400 sends overnight looks like a compromised account.

Time-of-day randomization — Emails are sent across business hours (8am–6pm prospect local time) with randomized minute-level timing. Not batch-fired at 9:00:00.

Day-of-week distribution — We send Tuesday through Thursday primarily. Monday and Friday send rates are lower. Weekends: zero.

Reply-thread seeding — The warmup network generates real reply threads, which are the strongest positive signal an inbox can have.

---

Monitoring

We check deliverability signals weekly:

Signal	Tool	Target
Inbox placement rate	GlockApps / Maildoso	>90% inbox
Bounce rate	Sending platform	<2%
Spam complaint rate	Google Postmaster	<0.1%
Blacklist status	MxToolbox	Clean
Domain reputation	Google Postmaster	High
Open rate (proxy)	Internal tracking	>35%

If any metric falls below threshold, we investigate before the next send day.

---

What causes spikes

Common triggers we watch for:

• List quality drops — New data source with higher invalids
• Copy flagged — A specific email triggers spam filters (words, link patterns, HTML formatting)
• Complaint spike — A batch that hit the wrong audience segment
• Volume surge — Sending significantly above the warmed level

When a spike happens, we pause, identify the source, fix it, and resume with a smaller batch to confirm the fix before going back to full volume.

---

The content layer

Technical setup aside, the email content itself affects deliverability:

What hurts:

• HTML-heavy emails (images, buttons, multi-column layouts)
• Multiple links in one email
• Spam trigger words (“free,” “guaranteed,” “act now”)
• Link shorteners (bit.ly, etc.)
• Attachments

What helps:

• Plain text or minimal HTML
• One link max per email (or none in early touches)
• Natural, conversational language
• Short emails (under 150 words)

All our copy defaults to near-plain-text. No images. No fancy footers. It looks like a colleague wrote it, because that’s what gets opened.

---

DMARC progression

We move DMARC through three phases:

1. p=none (first 30 days) — Monitor only. Get baseline data on alignment rates.
2. p=quarantine (day 31–60) — Failing emails go to spam, not inbox. Catches misconfigured spoofs.
3. p=reject (day 60+) — Failing emails are rejected outright. Maximum protection.

This progression protects your domains from spoofing while giving us time to confirm everything is aligned correctly.