Deliverability Overview
Deliverability is the percentage of your emails that successfully reach recipients' inboxes rather than being rejected or landing in spam. It's determined by sender reputation, list hygiene, content quality, and technical configuration.
What Affects Deliverability
Three major factors drive inbox placement:
Sender Reputation
Mail providers score your sending IP and domain based on bounce rates, complaint rates, and engagement. Poor reputation means spam folder or outright rejection.
List Hygiene
Sending to old, purchased, or unengaged lists leads to hard bounces and spam traps — signals that destroy reputation quickly.
Technical Setup
Valid SPF, DKIM, and DMARC records prove you control the sending domain and reduce the chance of being flagged as spoofed email.
Reputation Dashboard
EmailSendX provides a per-provider reputation dashboard under Workspace → Deliverability → Reputation. It shows your 7-day rolling metrics for each connected email provider (SES, SMTP servers).
| Metric | Green (good) | Yellow (warning) | Red (danger) |
|---|---|---|---|
| Bounce Rate | < 2% | 2% – 5% | > 5% |
| Complaint Rate | < 0.1% | 0.1% – 0.3% | > 0.3% |
| Delivery Rate | > 98% | 95% – 98% | < 95% |
Automatic send pause at 5% bounce rate
IP Warmup
New AWS SES accounts start in sandbox mode, which limits sending to verified email addresses only. Before sending to real audiences, you must request production access from AWS (SES → Account dashboard → Request production access). Approval typically takes 24–48 hours.
After sandbox lift, warm up your sending volume gradually. Sending large volumes from a new IP immediately triggers spam filters. EmailSendX recommends the following 14-day warmup curve:
| Day | Max daily volume |
|---|---|
| Day 1–2 | 200 emails |
| Day 3–4 | 400 emails |
| Day 5–6 | 800 emails |
| Day 7–8 | 1,600 emails |
| Day 9–10 | 3,200 emails |
| Day 11–12 | 6,400 emails |
| Day 13–14 | 12,800 emails |
| Day 15+ | Scale to target volume |
Send to your most engaged contacts first — recipients who have previously opened or clicked your emails. High engagement during warmup signals to mail providers that your emails are wanted.
Bounce & Complaint Handling
EmailSendX automatically handles bounces and complaints to protect your reputation:
Hard bounces
Permanent delivery failure (invalid email, non-existent domain). Contact status is automatically set to bounced and suppressed from future sends. EmailSendX also fires the email.bounced webhook event.
Soft bounces
Temporary failure (mailbox full, server temporarily unavailable). Soft bounces are logged but do not suppress the contact. After 3 consecutive soft bounces, the contact is auto-suppressed.
Spam complaints
Received via AWS SES feedback loops. Contact is automatically suppressed. If your 24-hour complaint rate exceeds 0.5%, an alert is sent to workspace admins.
Seed List Testing
Before sending a large campaign, test inbox placement across major email clients and providers using a seed list — a set of real mailboxes at different providers used specifically for testing.
Recommended seed testing services:
- GlockApps — shows inbox/spam placement per provider with spam score breakdown
- InboxGeek — seed list testing with provider-specific placement rates
Workflow: add the seed addresses to a test list in EmailSendX → send your campaign to just the test list → review the seed service report → fix any issues → send to your real audience.
Blacklist Monitoring
EmailSendX monitors your sending domain and IP against major real-time blacklists (RBLs) daily. Monitored lists include:
- Spamhaus (SBL, XBL, PBL)
- Barracuda Reputation Block List (BRBL)
- SORBS
- SpamCop
If your domain or IP is listed on any of these, you receive an immediate alert email with the listing details and instructions for requesting delisting. View current blacklist status in Workspace → Deliverability → Blacklist Monitor.
DNS setup is your first line of defense
Need to check your DNS setup?
Verify SPF, DKIM, and DMARC records are correctly configured for maximum deliverability.