Sparkforge ESP Block Policy: Email Sending Restrictions

By Sparkforge Support Team ·Last reviewed May 3, 2026

When Gmail, Yahoo, Outlook, and other providers reject too many of your emails, Sparkforge's ESP Block Policy temporarily suspends sending to protect your sender reputation. Block rates of 3% trigger warnings; 5% triggers a temporary suspension.

ESP blocks happen when major email providers (Gmail, Yahoo, Outlook, etc.) reject your mail for authentication failures, poor sender reputation, spammy content, or technical misconfiguration. Unlike normal bounces, ESP blocks are tracked separately and trigger sending restrictions to protect your long-term deliverability.

Policy timeline

The ESP Block Policy takes effect on 12 February 2026. Existing users get advance warning to clean up email practices. Current ESP block history resets on the implementation date.

Block thresholds

ESP block rate	Action	Duration	Block level
3%	Warning email sent	Immediate	Pre-block warning
5%	Email sending suspended	12 hours	1st block
3% (after 1st block)	Critical warning email sent	Immediate	Pre-2nd block warning
5% (after 1st block)	Email sending suspended	24 hours	2nd block
3% (after 2nd block)	Final warning email sent	Immediate	Pre-3rd block
5% (after 2nd block)	Permanent suspension	Permanent	3rd block

Blocks reset after 7 consecutive days of maintaining an ESP block rate below 1%. In the current release, suspensions are capped at 24 hours per block — permanent suspension is documented but not yet enforced.

What you'll see when blocked

A red banner appears at the top of the affected sub-account: "Email sending is blocked due to a high number of spam blocks from email providers."

Immediate steps when blocked

Open Bounce Classification: Sub-account Settings → Email Services → Bounce Classification. Review ESP block categories and the highest-volume issues.
Identify your primary issues: the dashboard shows DMARC failures, reputation issues, error volumes by provider (Gmail, Yahoo, Outlook), and recommended actions per block type.
Implement fixes: address authentication, content/template, list hygiene, and configuration problems.

How to prepare before enforcement

Email authentication

Configure SPF records to include Sparkforge's sending IPs.
Enable DKIM signing for your domain.
Implement a DMARC policy starting with p=none for monitoring.
Verify all DNS records.

List hygiene

Remove bounced and invalid addresses.
Use double opt-in for new subscribers.
Segment by engagement.
Remove subscribers inactive for 6+ months.

Content quality

Avoid spam trigger words and excessive promotional language.
Hold a roughly 60:40 text-to-image ratio.
Include a clear unsubscribe link.
Use professional, branded templates.
Run content through a spam-checking tool before sending.

Monitoring

Check the Bounce Classification dashboard daily.
Track engagement (opens, clicks, unsubscribes).
Set alerts for unusual bounce patterns.

FAQ

How do blocks reset?

After 7 consecutive days of maintaining ESP block rates below 1%. Three blocks within any 7-day window can lead to permanent suspension once that enforcement is active.

Can a permanent suspension be reversed?

Not automatically. A manual review by the Sparkforge support team is required, and unblocking is not guaranteed.

What if I'm currently above 3% ESP block rate?

Use the preparation period to fix the underlying issues. Block enforcement begins on 12 February 2026 — until then, the system is in monitoring/notification mode.

Frequently Asked Questions

When does the ESP Block Policy take effect?

The ESP Block Policy is scheduled to take effect on 12 February 2026, giving users time to audit and improve their email practices before enforcement begins.

How do ESP blocks reset?

Blocks reset after 7 consecutive days of maintaining an ESP block rate below 1%. Three blocks within a 7-day period can lead to permanent suspension once that enforcement is live.

Can a permanent ESP suspension be reversed?

Not automatically. A manual review by the Sparkforge support team is required, and unblocking is not guaranteed — it depends on compliance with email best practices.

How is an ESP block different from a normal bounce?

Regular bounces (invalid addresses, full mailboxes) are tracked and handled separately. ESP blocks reflect provider-level rejection for reputation, authentication, or policy issues and have their own threshold-based block system.

Will I get notified before email sending is suspended?

Yes. A warning email goes out at 3% ESP block rate, giving you time to take corrective action before the 5% threshold triggers a temporary suspension.