Email Queue

What Is the Email Queue?

The Email Queue manages outgoing emails created by Kraken Careers.

Instead of attempting to send every message at the same time, Kraken Careers places outgoing messages into a queue and processes them in order. This helps spread email activity across separate requests and reduces the chance of several automated messages being sent simultaneously.

The Email Queue can include messages such as:

  • Candidate communications
  • Application outcome notifications
  • Reviewer assignment notifications
  • Reference requests
  • Reference reminders
  • Interview and meeting information
  • Scheduled reminders
  • Other automated Kraken Careers messages

To open the Email Queue, go to Tools → Careers Email Queue.

Access Permissions

The Email Queue requires the WordPress manage_options permission. This permission is normally reserved for Administrators.

Authorized users can:

  • See how many emails are waiting
  • View queued recipients and subjects
  • See when each message was added
  • Review the email template source
  • Check the most recent send time
  • Process the entire queue immediately

The Email Queue contains recipient information and email subjects. Access should remain limited to trusted administrators.

How the Queue Works

When Kraken Careers creates an outgoing email:

  1. The message is added to the end of the queue.
  2. Kraken Careers attempts to process the next eligible message.
  3. Remaining messages stay in the queue.
  4. WordPress Cron checks the queue every 30 minutes.
  5. During normal processing, one queued email is processed at a time.
  6. The next message is processed during a later eligible request or scheduled queue run.

Messages are processed in the order they were added.

The queue uses a short cooldown between normal sends. This prevents separate requests from attempting to send queued messages at exactly the same time.

Automatic Processing Schedule

Kraken Careers registers a WordPress Cron event that checks the Email Queue every 30 minutes.

This is not an hourly batch. The current queue schedule is every 30 minutes, and a normal queue run processes one message.

WordPress Cron depends on the website receiving requests. On a low-traffic website, a scheduled queue event may run later than its intended time.

For more reliable timing, a server-level cron task can be configured to trigger WordPress Cron regularly. Contact your hosting provider or website administrator if scheduled emails are consistently delayed.

Immediate Queue Processing

When a message is first queued, Kraken Careers may process one waiting email immediately if the queue cooldown allows it.

If another email was processed recently, the new message remains in the queue until a later request or Cron run.

This means some messages may leave the queue shortly after they are created, while others wait for automatic processing.

Understanding the Queue Screen

The Email Queue screen displays:

  • The number of emails currently waiting
  • The recorded time of the most recent queue send
  • A button for sending all queued emails immediately
  • A table containing the waiting messages

If no messages are waiting, the table displays The queue is empty.

Queue Table

Each waiting message appears as a row in the queue table.

Queued At

Shows the date and time the message was added to the queue.

The date and time use the WordPress site settings.

Older queue records created before queue timestamps were introduced may display Unknown.

Recipient

Shows the primary email address or addresses that will receive the message.

When a message has multiple recipients, the addresses are displayed together.

BCC and Reply-To addresses are not displayed in this table.

Subject

Shows the subject line of the queued email.

If no subject is available, the table displays (No subject). A message without a valid subject cannot be successfully prepared by the mailer.

Source

Shows the filename of the email template used to build the message.

This can help administrators identify the type of automated email. If the template source is unavailable, the table displays Unknown.

The Source value is the template filename, not necessarily a plain-language communication category.

Last Send

The Last send value shows when the queue most recently processed an email entry.

If no queue send has been recorded, the page displays:

Last send: not yet recorded

This timestamp confirms that the queue processed an item. It does not independently confirm that the recipient’s mail provider accepted or delivered the email.

Send Queued Emails Now

The Send queued emails now button forces Kraken Careers to process all messages currently waiting in the queue.

To send the queue immediately:

  1. Go to Tools → Careers Email Queue.
  2. Review the number of waiting emails.
  3. Review the recipients and subjects.
  4. Select Send queued emails now.
  5. Wait for the page to reload.
  6. Review the confirmation notice and remaining queue count.

Forced processing ignores the normal cooldown and continues until the current queue is empty.

The confirmation notice reports how many queue entries were processed.

When to Send the Queue Manually

Manual queue processing may be appropriate when:

  • A time-sensitive candidate communication is waiting
  • A reviewer needs an assignment notification immediately
  • Reference requests must be sent promptly
  • WordPress Cron has been delayed
  • You are testing email configuration
  • A small number of messages need immediate processing

For routine delivery, allow the automatic queue processor to handle messages.

Warning About Large Queues

Sending the entire queue immediately can create a sudden burst of email activity.

A large forced send may:

  • Exceed hosting email limits
  • Trigger SMTP rate limits
  • Cause temporary mail-provider rejection
  • Increase spam filtering
  • Affect server performance
  • Damage the sending domain’s reputation

Review the queue count before using Send queued emails now.

If the queue contains a large number of messages, confirm your hosting or SMTP provider’s sending limits before forcing the queue.

What Happens After Processing

A processed queue entry is removed from the waiting queue.

Kraken Careers sends the message using the WordPress wp_mail() system. Actual delivery depends on the website’s mail configuration, hosting environment, SMTP service, DNS records, and the recipient’s email provider.

The Email Queue does not provide:

  • Delivery receipts
  • Open tracking
  • Click tracking
  • Bounce tracking
  • Per-message delivery statuses
  • A sent-email archive
  • Individual retry controls

Use an SMTP or transactional email service with delivery logging when detailed delivery information is required.

Failed Email Attempts

The current queue does not automatically retain a processed message for retry when wp_mail() reports a failure.

A queue entry can therefore disappear after processing even when the message was not successfully handed off by WordPress.

The processed count shown after a forced send represents queue entries processed. It should not be treated as proof that every email was delivered.

If a message is important:

  1. Check the SMTP or mail-provider logs.
  2. Confirm the recipient address.
  3. Confirm the sending address and domain.
  4. Correct the underlying email problem.
  5. Return to the candidate or related record.
  6. Send the communication again.

Individual Queue Controls

The current Email Queue does not provide buttons to:

  • Send one selected message
  • Cancel an individual message
  • Edit a queued recipient
  • Edit a queued subject
  • Preview queued email content
  • Retry a specific failed message

The Send queued emails now button processes the complete queue.

Before sending a communication from a candidate record, use the available preview tools to confirm the email and candidate-facing linked content.

Email Content

Queued emails are sent as HTML emails using Kraken Careers templates.

Depending on the communication, a queued email can include:

  • Primary recipients
  • BCC recipients
  • Reply-To addresses
  • Sender name
  • Sender email address
  • Subject
  • Rendered HTML content
  • Attachments
  • Template data

If the configured sender address is invalid, Kraken Careers falls back to the WordPress administration email address.

If the sender name is empty, Kraken Careers falls back to the WordPress site name.

Attachments

Some queued communications can include file attachments.

An attachment must still exist and be readable when the email is processed. If a file is deleted, moved, or inaccessible while the message waits in the queue, the email may fail or be sent without the expected file depending on the mail system.

Avoid deleting communication attachments until the relevant message has left the queue.

Email Delivery Requirements

The Email Queue organizes when Kraken Careers asks WordPress to send messages. It does not configure email delivery by itself.

Reliable delivery may require:

  • A valid From address
  • A domain-based sending address
  • Correct SPF records
  • Correct DKIM records
  • A suitable DMARC policy
  • A configured SMTP or transactional email service
  • Adequate sending limits
  • Working WordPress Cron
  • A functioning wp_mail() configuration

For production websites, a dedicated SMTP or transactional email provider is generally more reliable than basic server mail.

Troubleshooting

The Queue Keeps Growing

If new messages are being added but the queue is not decreasing:

  1. Confirm that WordPress Cron is working.
  2. Check whether the site receives regular traffic.
  3. Review the website’s Site Health information.
  4. Check for disabled WordPress Cron settings.
  5. Review PHP and WordPress error logs.
  6. Confirm that the database can update WordPress options.
  7. Test the mail system.
  8. Ask the hosting provider whether scheduled events are running.

You can use Send queued emails now for a small queue after confirming the mail configuration.

Emails Remain in the Queue Longer Than 30 Minutes

The queue is checked by WordPress Cron every 30 minutes, but WordPress Cron does not run continuously. It normally runs when the website receives a request after an event becomes due.

A low-traffic site may therefore process the queue late.

Configure a server cron task when more dependable timing is required.

The Queue Is Empty but the Email Was Not Received

An empty queue means the message was processed, not that it reached the recipient’s inbox.

Check:

  • The recipient address
  • Spam or junk folders
  • SMTP logs
  • Mail-provider activity logs
  • WordPress mail errors
  • SPF, DKIM, and DMARC records
  • Hosting sending limits
  • From-address configuration
  • Recipient-domain blocking

“Emails Were Sent” Appears but Recipients Did Not Receive Them

The notice counts processed queue entries. It is not a delivery confirmation.

Check your SMTP provider or email service for the final status of each message.

The Email Queue Page Is Missing

The page is available under Tools → Careers Email Queue only to users with the required administrator-level permission.

Confirm that:

  • You are logged in as an Administrator
  • Your role has the manage_options permission
  • Kraken Careers is active
  • The plugin is up to date

The Source Shows Unknown

The queued entry does not contain a recognizable template path.

The recipient and subject may still help identify the communication. If the message cannot be identified safely, investigate how it was created before forcing the queue.

The Recipient or Subject Is Incorrect

The current queue screen does not allow editing a queued entry.

Do not force the queue until you have considered the impact on the incorrect message. Because there is no individual cancellation control, an administrator may need technical assistance to safely remove or correct an invalid queued entry.

After resolving it, return to the relevant candidate, reference, schedule, or communication record and create the message again.

Recommended Administrative Review

Administrators should periodically:

  1. Open Tools → Careers Email Queue.
  2. Check whether the queue is growing unexpectedly.
  3. Review how long the oldest message has been waiting.
  4. Confirm that recipients and subjects look valid.
  5. Check the Last Send time.
  6. Review SMTP or mail-provider logs when messages appear delayed.
  7. Use manual processing only when appropriate.
  8. Investigate repeated queue or delivery problems.

The Email Queue helps control outgoing Kraken Careers email activity, but reliable delivery still depends on a properly configured WordPress mail system.