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Bounce Addresses

A bounce address is essential for receiving delivery reports of failed messages and plays a key role in authenticating emails via SPF (Sender Policy Framework). It ensures your emails are fully qualified and recognized.

Overview​

Bounce processing automatically handles delivery failures:

+------------------+      +------------------+      +------------------+
|  EMAIL BOUNCES   | ---> |  BOUNCE ADDRESS  | ---> |  PROCESSING      |
|  (undeliverable) |      |  (IMAP/POP)      |      |  ENGINE          |
+------------------+      +------------------+      +------------------+
                                                           |
                                                           v
                                                   +------------------+
                                                   |  LIST UPDATES    |
                                                   |  - Mark bounced  |
                                                   |  - Update status |
                                                   |  - Clean lists   |
                                                   +------------------+

Why Bounce Processing Matters​

List Hygiene​

  • Remove invalid addresses - Stop sending to addresses that don't exist
  • Reduce complaints - Clean lists have better engagement
  • Save resources - Don't waste sends on undeliverable addresses

Deliverability​

  • Protect sender reputation - High bounce rates hurt reputation
  • Avoid blacklisting - Consistent bounces can trigger blocks
  • Improve inbox placement - Clean lists mean better delivery

SPF Authentication​

  • Email authentication - Bounce address is part of SPF validation
  • Fully qualified emails - Ensures proper email identification
  • Reduced spam flagging - Authenticated emails are trusted

Viewing Bounce Addresses​

Navigate to Setup → Bounce Addresses to view all configured addresses.

Page Features​

  • Add New button to create a bounce address
  • Our records / User records toggle to filter view
  • Filter by admin dropdown to filter by administrator
  • Show entries dropdown to control page size
  • Search box to find specific addresses
  • Bulk Actions dropdown for batch operations

Bulk Actions​

Select one or more addresses using checkboxes, then choose from:

ActionDescription
Test ConnectionVerify selected addresses can connect
Set as ActivateEnable selected addresses
Set as InactiveDisable selected addresses
Export to CSV FileDownload selected addresses

Table Columns​

ColumnDescription
Bounce Email AddressThe email address receiving bounces
Server HostIMAP/POP3 server hostname
UsernameLogin username
Connection MethodPOP or IMAP
Server PortPort number
ErrorConnection error status (if any)
ActionsRow action menu

Row Actions​

Click the ... (three dots) menu on any row to access:

ActionDescription
Test ConnectionVerify this address can connect
Set as ActivateEnable this address
Set as InactiveDisable this address
Export to CSV FileDownload this address configuration
EditModify address settings
DeleteRemove this address

Creating a Bounce Address​

Navigate to Setup → Bounce Addresses and click Add New.

Basic Settings​

Bounce Email Address *​

Enter the email address that will receive bounce notifications.

Examples:

Dedicated Bounce Address

Use a dedicated email address solely for bounce processing. Don't use a regular mailbox that receives other emails.

Process bounces from the mailbox​

Toggle to enable automatic bounce processing from this mailbox.

When enabled:

  • System periodically checks the mailbox
  • Bounce notifications are parsed
  • Contact statuses are updated
  • Bounced addresses are marked accordingly

Active​

Toggle to enable or disable the bounce address. Inactive addresses are not processed.

Connection Settings​

Connection Method *​

Select the mail retrieval protocol:

ProtocolDescriptionUse Case
POPPost Office ProtocolDownload and optionally delete
IMAPInternet Message Access ProtocolKeep emails on server, more features

Recommendation: IMAP is preferred for bounce processing as it allows better message management.

Post-Processing Email Deletion​

Toggle to delete emails after they have been processed.

When enabled:

  • Processed bounce emails are removed from mailbox
  • Prevents reprocessing of same bounces
  • Keeps mailbox clean

Recommendation: Enable to prevent mailbox overflow and duplicate processing.

Server Configuration​

Server Hostname *​

Enter the IMAP or POP3 server address.

Common hosts:

ProviderIMAP HostPOP3 Host
Gmailimap.gmail.compop.gmail.com
Outlookoutlook.office365.comoutlook.office365.com
Yahooimap.mail.yahoo.compop.mail.yahoo.com
Customimap.yourdomain.compop.yourdomain.com

Username *​

The login username for the email account. Usually the full email address.

Examples:

Password​

The password for the email account (stored encrypted).

App Passwords

For Gmail, Outlook, and other providers with two-factor authentication, you may need to create an app-specific password.

Port Number *​

Enter the server port number.

Common ports:

ProtocolPortSecurity
IMAP143None/STARTTLS
IMAP993SSL/TLS
POP3110None/STARTTLS
POP3995SSL/TLS

Mailbox Folder *​

Specify the mailbox folder to check for bounces.

Default: INBOX

Other options:

  • INBOX - Main inbox
  • Bounces - Custom folder if filtering
  • INBOX.Bounces - Subfolder notation

Security Settings​

Validate Certificate​

Select whether to verify server SSL certificates:

OptionDescription
YesValidate certificate (recommended for production)
NoSkip validation (use for self-signed certificates)
warning

Only disable certificate validation for trusted internal servers or during testing.

Use Secure Connection​

Select the connection security type:

OptionDescription
NoneNo encryption (not recommended)
SSLImplicit SSL/TLS encryption
TLSSTARTTLS encryption

Recommendation: Always use SSL or TLS for security.

Verifying and Saving​

Verify Connection​

Click the Verify Connection button to test the settings before saving.

The verification checks:

  • Server is reachable
  • Credentials are valid
  • Folder is accessible
  • Protocol works correctly

Save​

Click Save to create or update the bounce address.

Cancel​

Click Cancel to discard changes and return to the list.

Managing Bounce Addresses​

Editing an Address​

  1. Click the ... menu on a bounce address
  2. Select Edit
  3. Modify settings as needed
  4. Click Verify Connection to test changes
  5. Click Save

Testing Connection​

Test a single address:

  1. Click the ... menu on a bounce address
  2. Select Test Connection
  3. View success or error message

Test multiple addresses:

  1. Select addresses using checkboxes
  2. Click Bulk Actions → Test Connection
  3. View results for each address

Activating/Deactivating​

Single address:

  1. Click the ... menu
  2. Select Set as Activate or Set as Inactive

Multiple addresses:

  1. Select addresses using checkboxes
  2. Click Bulk Actions → Set as Activate or Set as Inactive

Deleting an Address​

  1. Click the ... menu on a bounce address
  2. Select Delete
  3. Confirm deletion
warning

Deleting a bounce address used by sending nodes requires updating those nodes first.

Exporting to CSV​

Single address:

  1. Click the ... menu
  2. Select Export to CSV File

Multiple addresses:

  1. Select addresses using checkboxes
  2. Click Bulk Actions → Export to CSV File
  3. Download the CSV file

Assigning to Sending Nodes​

Configuring Return Path​

When creating or editing a sending node:

  1. Navigate to bounce processing settings
  2. Enable Return Path
  3. Select a bounce address from the dropdown
  4. Save the node

How It Works​

  1. Outgoing emails include the bounce address in the Return-Path header
  2. When delivery fails, the bounce notification is sent to this address
  3. The bounce address periodically processes new bounces
  4. Contact statuses are updated based on bounce type

Best Practices​

Address Setup​

  • Use dedicated addresses - Don't mix bounce mail with regular email
  • Create before sending - Set up bounce addresses before campaigns
  • Use reliable providers - Choose stable email services
  • Configure SSL/TLS - Always use encrypted connections

Processing Configuration​

  • Enable post-processing deletion - Prevent reprocessing of handled bounces
  • Check regularly - Ensure bounce processing is running
  • Monitor error column - Watch for connection issues
  • Review periodically - Check for processing errors

Security​

  • Strong passwords - Use complex, unique passwords
  • App passwords - Use provider app passwords when available
  • Limited access - Don't use admin accounts for bounce processing
  • Regular rotation - Change passwords periodically

Troubleshooting​

Connection Failed​

Possible causes:

  • Incorrect server host or port
  • Firewall blocking connection
  • Server not responding
  • Protocol mismatch

Solutions:

  • Verify server details with email provider
  • Check firewall allows mail ports
  • Try alternative ports
  • Confirm protocol (IMAP vs POP)

Authentication Error​

Possible causes:

  • Wrong username or password
  • Two-factor authentication blocking
  • Account locked or disabled
  • App password required

Solutions:

  • Verify credentials
  • Generate app-specific password
  • Check account status
  • Review provider security settings

Bounces Not Processing​

Possible causes:

  • Address status is inactive
  • Processing toggle disabled
  • Wrong folder configured
  • Cron job not running

Solutions:

  • Set address as active
  • Enable "Process bounces from the mailbox"
  • Verify folder name (case-sensitive)
  • Check system cron configuration

Error Column Shows Issues​

Possible causes:

  • Connection timeout
  • Authentication failure
  • Server unavailable
  • Certificate issues

Solutions:

  • Check error message details
  • Verify server is online
  • Test connection manually
  • Adjust certificate validation setting

Provider-Specific Setup​

Gmail​

Settings:

  • Host: imap.gmail.com
  • Port: 993
  • Connection Method: IMAP
  • Secure Connection: SSL

Requirements:

  1. Enable IMAP in Gmail settings
  2. Enable "Less secure app access" OR
  3. Generate App Password (recommended if 2FA enabled)

Outlook/Office 365​

Settings:

  • Host: outlook.office365.com
  • Port: 993
  • Connection Method: IMAP
  • Secure Connection: SSL

Requirements:

  1. IMAP enabled for account
  2. App Password if MFA enabled

Custom Mail Server​

Settings:

  • Host: Your mail server address
  • Port: 993 (IMAP SSL) or 143 (IMAP)
  • Connection Method: IMAP preferred
  • Secure Connection: SSL or TLS

Next Steps​

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