# Action Scheduler issues

Source: https://catalystgroup.gg/docs/email-delivery/action-scheduler-issues/
Updated: 2026-10-19 · By Duane Garner

Fix past-due background tasks, disabled WP-Cron and large task queues that delay queued emails, summaries and clean-ups in CRM-NG SMTP.

CRM-NG SMTP runs some work in the background with a library called **Action Scheduler**. When background tasks stop running, queued emails are delayed and clean-ups do not happen. This article explains what runs in the background and how to fix common problems. It is for administrators and developers.

 

## What runs in the background

 

CRM-NG SMTP's background tasks belong to the group `crmng_smtp`. They include:

 
- **Sending queued emails** — when **Optimize Email Sending** or **Email Rate Limiting** is on (**CRM-NG SMTP → Settings → Misc**), emails wait in a queue and a background task sends them.
- **Processing and cleaning the queue.**
- **Cleaning up old debug events** — according to the **Events Retention Period**.
- **Sending email summaries.**

 

If you do not use the email queue, a stalled task usually just means late clean-ups. If you do use it, stalled tasks mean **emails are not sent**.

 

## Where to see the tasks

 

Go to **CRM-NG SMTP → Tools → Scheduled Actions**. The table lists tasks with their status: **Pending**, **In-progress**, **Complete**, **Failed** or **Canceled**, and when each is due.

 

Action Scheduler is shared with other plugins, such as WooCommerce. You may see tasks that have nothing to do with CRM-NG SMTP. Search for `crmng_smtp` to show only ours.

 

## How tasks get run

 

Action Scheduler is triggered by **WP-Cron**, WordPress's built-in scheduler. WP-Cron does not run on a clock: it runs when someone visits the site. On a quiet site, or a site where WP-Cron is switched off, tasks wait until the next trigger.

 

## Problem: past-due actions

 

You see pending tasks whose due time has passed, sometimes with a notice about past-due actions.

 
1. Check for traffic
  On a low-traffic site, tasks may simply be waiting for a visit. Load a page on the site and check again after a minute.
2. Check whether WP-Cron is disabled
  Look in `wp-config.php` for `define( 'DISABLE_WP_CRON', true );`. If it is there, a real server cron job must call WordPress instead (next section).
3. Check Site Health
  Go to **Tools → Site Health**. WordPress reports if scheduled events are failing or late, and if background requests to your own site (loopback requests) are blocked.
4. Run the tasks by hand
  In **Scheduled Actions**, hover over a pending task and click **Run**. If it fails, the log for that task shows why.

 

Loopback requests are often blocked by a security plugin, a firewall, HTTP authentication on a staging site, or a server that cannot resolve its own domain. Your host can help with the last two.

 

## Problem: WP-Cron is disabled

 

Many hosts and performance guides recommend `DISABLE_WP_CRON` and a real cron job instead. That is fine, as long as the cron job exists. Ask your host, or add one in your control panel's **Cron Jobs** page, to run every five minutes. Either of these works:

 

```
*/5 * * * * wget -q -O - "https://yourdomain.com/wp-cron.php?doing_wp_cron" >/dev/null 2>&1
```

 

```
*/5 * * * * cd /path/to/wordpress && wp cron event run --due-now >/dev/null 2>&1
```

 

To clear a backlog straight away with WP-CLI:

 

```
wp action-scheduler run --group=crmng_smtp
```

 

## Problem: a very large queue

 

Signs: the **Scheduled Actions** page loads slowly, or shows tens of thousands of entries.

 
- **Completed and canceled tasks are cleared automatically** after a retention period (about a month by default). A large number of them is normal on a busy site and not a problem in itself.
- **Many pending queued-email tasks** mean emails are arriving faster than they can be sent. Check your **Email Rate Limiting** values are not set too low for your normal volume, and that your mail service is not refusing messages (see [Debug events](https://catalystgroup.gg/docs/email-delivery/debug-events/)).
- **Many failed tasks** point to a real error. Open one and read its log.
- **Tasks from other plugins** can swamp the table. That is up to those plugins, but it slows everything that uses Action Scheduler, including ours.

 

## Problem: tasks fail with a database error

 

If tasks fail with errors about missing tables, check **Tools → Site Health** for *"CRM-NG SMTP DB tables check has failed"* and use its link to create the missing tables. See [Site Health checks](https://catalystgroup.gg/docs/email-delivery/site-health-checks/).

 

## When to turn the queue off

 

If you cannot get background tasks running reliably on your host, turn off **Optimize Email Sending** on the **Misc** tab. Emails are then sent immediately while the page loads, which does not depend on background tasks. See [Miscellaneous settings](https://catalystgroup.gg/docs/email-delivery/misc-settings/).

 

## Related

 
- [Scheduled actions](https://catalystgroup.gg/docs/email-delivery/scheduled-actions/)
- [Miscellaneous settings](https://catalystgroup.gg/docs/email-delivery/misc-settings/)
- [Site Health checks](https://catalystgroup.gg/docs/email-delivery/site-health-checks/)
- [Troubleshooting email delivery](https://catalystgroup.gg/docs/email-delivery/troubleshooting/)