email-deliverability

plugin: instantly updated: 2026-01-20

Email Deliverability

Deliverability Fundamentals

Key Metrics

Metric	Healthy	Warning	Critical
Bounce Rate	<2%	2-5%	>5%
Spam Complaint Rate	<0.1%	0.1-0.5%	>0.5%
Inbox Placement	>95%	80-95%	<80%
Sender Score	>80	60-80	<60

Deliverability Components

DELIVERABILITY =
  Sender Reputation (40%)
  + Content Quality (30%)
  + Technical Setup (20%)
  + List Quality (10%)

Sender Reputation

Warm-Up Schedule

Day	Emails/Day	Total Sent
1-7	10-20	70-140
8-14	30-50	280-490
15-21	75-100	805-1190
22-28	150-200	1855-2590
29+	Scale gradually	-

Reputation Signals

Positive Signals	Negative Signals
Opens	Spam complaints
Replies	Hard bounces
Clicks	Low engagement
Forwards	Unsubscribes
Non-spam marking	Spam trap hits

Content Quality

Spam Filter Triggers

High-Risk Words:

FREE, GUARANTEE, WINNER, CASH, PRIZE
URGENT, ACT NOW, LIMITED TIME
Click here, Click below, Don't miss
Make money, Extra income, Work from home

Formatting Red Flags:

• ALL CAPS in subject or body
• Multiple exclamation marks!!!
• Colored fonts
• Excessive links (>1)
• Images (especially in cold email)
• Attachments

Safe Practices

Do	Don't
Plain text emails	HTML-heavy templates
Single link (if any)	Multiple CTAs
Conversational tone	Salesy language
Short sentences	Long paragraphs
Proper grammar	Typos and errors

Technical Setup

Required DNS Records

Record	Purpose	Status Check
SPF	Authorize sending servers	nslookup -type=TXT domain
DKIM	Email signature verification	Check in email headers
DMARC	Policy for failed checks	nslookup -type=TXT _dmarc.domain

Recommended Settings

SPF: v=spf1 include:_spf.instantly.ai ~all
DKIM: Configure via Instantly dashboard
DMARC: v=DMARC1; p=none; rua=mailto:dmarc@yourdomain.com

List Quality

Email Verification

Verification Level	Description	Bounce Rate
Syntax check	Valid format	Reduces 5-10%
Domain check	Valid domain	Reduces 10-20%
Mailbox check	Exists	Reduces 20-40%
Engagement check	Active	Reduces 5-15%

List Hygiene

Practice	Frequency	Impact
Remove hard bounces	Immediately	Critical
Remove soft bounces	After 3 attempts	High
Remove unsubscribes	Immediately	Critical
Re-verify list	Every 3 months	Medium

Troubleshooting

High Bounce Rate (>5%)

Diagnosis Steps:

1. Check bounce types (hard vs soft)
2. Identify source (specific list segment?)
3. Verify emails before adding to campaign

Remediation:

1. Pause campaign immediately
2. Remove all hard bounces
3. Re-verify remaining list
4. Resume with verified emails only

Low Open Rate (<15%)

Possible Causes:

1. Poor sender reputation
2. Landing in spam/promotions
3. Bad subject lines
4. Wrong send time

Diagnosis:

1. Check sender score
2. Send test emails to Gmail/Outlook
3. Review recent changes to sending

Spam Complaints (>0.1%)

Immediate Actions:

1. Pause campaign
2. Review targeting (wrong ICP?)
3. Check email frequency
4. Review unsubscribe visibility

Long-term:

1. Improve list sourcing
2. Better qualification
3. Add clear opt-out

Recovery Playbook

Reputation Recovery

Day	Action	Expected Outcome
1-3	Pause all sending	Stop damage
4-7	Remove problem addresses	Clean list
8-14	Warm up from scratch	Rebuild slowly
15-21	Monitor metrics closely	Catch issues early
22+	Gradually scale	Sustainable growth

Blacklist Removal

1. Identify which blacklists (MXToolbox)
2. Fix underlying issue first
3. Request removal from each list
4. Wait 24-72 hours
5. Re-check and repeat if needed