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Advanced Email Deliverability
Sunset flows and reputation repair.
SiteBartar Research · Updated June 2026
Diagnose placement
Drop in opens may be spam folder not disinterest — seed tests to Gmail, Outlook, and Apple inboxes weekly.
Google Postmaster Tools for domain reputation trends — sudden dips follow imports or DNS changes.
Check bounce rate spikes after imports — hard bounces must be removed immediately.
good-newsletter-open-rate context by list size — compare to your baseline, not internet averages.
Segment new vs old subs — placement problems often isolate to one signup source.
Sunset flows
Re-engage 90-day inactive with 3-email win-back; remove hard bounces immediately.
ConvertKit/Beehiiv automation for win-back — stop sequence on click or reply.
Never mail entire stale Mailchimp import day one — warm engaged segment first.
switch-mailchimp-creator warm-up section for ESP migration context.
Paid subscribers need careful sunset — offer pause before delete; billing may remain active.
Get your personalized match
Answer a few questions — get a personalized match with reasons.
Take the Find Your Newsletter Platform quiz (~2 min)Authentication
SPF + DKIM + DMARC aligned on sending domain — all three required for serious volume.
Custom domain required for serious creators — substack-custom-domain parallel for any ESP.
Dedicated subdomain for marketing vs transactional optional at scale.
Fix DNS before scaling ads — broken auth wastes ad spend on spam folder placement.
Re-verify DNS after domain registrar changes — MX/TXT records break silently.
Content signals
Balance links/images; avoid spam trigger patterns in subject and body.
Consistent From name and send schedule — random senders train spam filters.
Honest subject lines — engagement feedback loops punish bait-and-switch.
Affiliate-heavy issues need more plain-text balance and fewer URL shorteners.
Test plain-text version if HTML placement fails — some segments prefer minimal HTML.
Recovery timeline
4–8 weeks typical after major reputation hit — patience beats blasting through it.
Reduce volume to engaged segment only during recovery.
email-deliverability-creators hub for basics before advanced tactics.
best newsletter platform if switching ESP after repeated placement failure.
Document every change (DNS, import, frequency) — correlate with Postmaster trends.
Browse the full directory
See ranked newsletter platforms with methodology — not pay-to-win lists.
Best Email Marketing & Newsletter Software (2026) →Get your personalized match
Answer a few questions — get a personalized match with reasons.
Take the Find Your Newsletter Platform quiz (~2 min)Frequently asked questions
Fix spam folder?
Auth DNS, sunset cold subs, reduce links, warm domain — this page walks advanced recovery after basics.
Substack deliverability?
Shared infra generally solid; your custom domain auth still matters for From-address trust.
Import 10K list?
Segment warm engaged first — never full blast; expect 4–8 week recovery if reputation was weak.
Dedicated IP?
Rare for creators under 100K — ESP shared pools usual unless enterprise contract.
Affiliate bias?
No — editorial-standards; deliverability advice is platform-agnostic.
Updates?
Quarterly review — Gmail and Outlook filter rules evolve; re-test seed inboxes.
Sources
- Official vendor documentation — verify before purchase
- SiteBartar editorial-standards
Disclosure: SiteBartar may earn commissions when you click partner links. Affiliate relationships never change match order or editorial scores. Full affiliate disclosure