Who This Is For / When to Use
Use this article if:
Email sending is suddenly suspended
You received a bounce-related compliance email
Campaigns or workflows stopped sending emails
You want to prevent future email sending suspensions
You need to understand bounce thresholds and recovery steps
What Is an Email Bounce
A bounce occurs when an email cannot be delivered to the recipient and is rejected by the recipient’s email provider.
Types of Email Bounces
Hard Bounce
The email address does not exist
The domain is invalid
The address was previously marked as permanently undeliverable
Soft Bounce
Temporary delivery failure
Examples include:
Mailbox full
Recipient server temporarily unavailable
Temporary throttling by the provider
Only hard bounces contribute directly to email sending suspensions.
Why Email Sending Is Suspended
Kyrios continuously monitors bounce rates to comply with industry deliverability standards.
Acceptable bounce rate: 0–3%
Warning threshold: above 3%
Suspension threshold: above 5%
If your account exceeds the suspension threshold:
Email sending is disabled
All other Kyrios features continue to work
The suspension applies only to outbound email
A high bounce rate indicates emails are being sent to invalid or non-existent addresses or that providers are blocking delivery due to poor past sending behavior.
Suspension Duration and Escalation Rules
Temporary Suspension
Email sending is blocked for 24 hours
You may resume sending sooner by enabling Email Validation
Repeated Violations
If suspension occurs three times within seven days
Email sending is blocked until Email Validation is enabled
Manual review by Support may be required
How to Fix a Hard Bounce Suspension
When email sending is suspended, Kyrios sends a notification to the account email address.
Required Actions
Review recent campaigns, workflows, and bulk sends
Stop all campaigns, workflows, triggers, and bulk actions targeting contacts without explicit email opt-in
Validate all contact email addresses
Prepare proof of compliance, including:
Opt-in forms or funnels
Examples of unsubscribe links used
Confirmation of consent language
Reactivation Process
Respond to the suspension email with the required proof
Complete email validation
The Kyrios Support Team reviews and assists with reactivation
How to Prevent Future Email Sending Suspension
1. Validate Contact Emails
Validate all existing contacts before sending
Invalid and bounced emails are automatically marked as Invalid
Invalid emails are excluded from campaigns, workflows, and bulk sends
Re-validation every 90 days is strongly recommended
2. Set Up a Dedicated Sending Domain
Using a dedicated domain improves reputation and isolation.
Configure:
Dedicated sending domain
DNS records as instructed in Kyrios domain setup documentation
3. Match Sender Email to the Dedicated Domain
Sender email addresses should align with the configured domain.
Example:
Sending domain:
replies.yourcompany.comSender email:
[email protected]
Misalignment increases bounce and spam risk.
4. Send Emails in Smaller Batches
Gradual sending reduces provider throttling and bounce spikes.
Avoid large bulk sends to unverified lists
Stagger campaigns and bulk actions
5. Use Double Opt-In
Double opt-in confirms consent before sending emails.
Recommended for:
Forms
Funnels
High-volume lead sources
Include an explicit consent checkbox in forms when collecting email addresses.
6. Always Include Unsubscribe Links
Every email must include a clear unsubscribe option.
This:
Reduces spam complaints
Improves compliance
Protects long-term deliverability
Common Questions
What is a hard bounce?
A hard bounce occurs when an email is returned because the recipient address is invalid or does not exist.
How long is email sending suspended?
First or second suspension: 24 hours
Third suspension within seven days: blocked until Email Validation is enabled
How do I reactivate email sending?
Stop problematic sends, validate all contacts, and respond to the suspension email with proof of opt-in. Support will guide reactivation.
What is a good bounce rate?
A healthy bounce rate is 0–3%. Rates above 5% may trigger suspension.
Can I just delete bounced contacts?
Deleting helps, but Kyrios already marks bounced emails as Invalid, preventing future sends. Full list validation is required to prevent recurrence.
What This Suspension Does Not Affect
Email bounce suspension does not disable:
Contacts
CRM features
Automations (non-email)
Reporting
Conversations
Other communication channels
Only email sending is restricted.