# Using CRM-NG SMTP with the CRM-NG family

Source: https://catalystgroup.gg/docs/email-delivery/using-with-crm-ng/
Updated: 2026-10-19 · By Duane Garner

How CRM-NG SMTP works with CRM-NG and CRM-NG Marketing: the Email delivery setup step, campaigns, the failing-email warning and which plugin sends.

CRM-NG SMTP works on its own, on any WordPress site. If you also run CRM-NG and CRM-NG Marketing, it plugs into them so invoices, ticket replies and campaigns all go through the mail service you set up. This article explains how the pieces fit. It is for CRM-NG customers.

 

## Which plugin sends your email

 

CRM-NG Marketing includes its own **Email Delivery** part, which you switch on under **Settings → Modules → Email Delivery** in CRM-NG. CRM-NG SMTP is the standalone version of the same job, with more mailers and tools.

 

Only one of them sends at a time:

 
- If CRM-NG SMTP is **sending** (it was installed on a site with nothing else sending, or you pressed **Make CRM-NG SMTP send my email**), CRM-NG uses it.
- If CRM-NG SMTP is in **standby**, the Email Delivery part keeps sending until you switch. See [Switching from another mail plugin (hand-over)](https://catalystgroup.gg/docs/email-delivery/switching-from-another-mail-plugin/).

 

CRM-NG Marketing follows whichever one is in charge automatically. You do not need to change any CRM-NG setting when you switch.

 

## The Email delivery setup step

 

CRM-NG's setup includes an optional **Email delivery** step. It shows which mail service is in use (*"Currently: …"*) and lets you set:

 
- **Sender name**
- **Sender address**
- **Mail service** — a list of the available mailers.

 

These fields write to CRM-NG SMTP's own settings when CRM-NG SMTP is sending. Choosing a service in this step does not connect it. Follow the links in the step to the **Email Delivery** screen (CRM-NG SMTP's **Settings** page) to enter the key or sign in, then send a test email.

 

If nothing is set up to send, the step says so and asks you to activate the **CRM-NG SMTP Email** plugin, or switch on Email Delivery, and then run the step again.

 

If your mail settings are fixed in `wp-config.php` with `CRMNG_SMTP_` constants, the step shows "These settings are fixed in wp-config.php on this site, so they can only be changed there."* and does not change anything. See [Securing settings with wp-config constants](https://catalystgroup.gg/docs/email-delivery/secure-settings-constants/).

 

## Campaigns

 

When CRM-NG SMTP is sending, CRM-NG Marketing campaigns go out through your configured mailer, the same as every other site email.

 
- **Reports read CRM-NG SMTP's email log.** The campaign reports and the **Mail delivery health** card count what the mail logger saw, including invoices, notifications and replies. Keep **Enable local email logging** on (**CRM-NG SMTP → Settings → Email Log**) so these numbers work. See [Setting up the email log](https://catalystgroup.gg/docs/email-delivery/email-log-setup/).
- **Tracking.** Campaigns use CRM-NG Marketing's own open and click tracking, set up in CRM-NG Marketing.
- **Volume.** Large campaigns can hit your mail service's limits. Choose a service suited to volume and consider [Email rate limiting](https://catalystgroup.gg/docs/email-delivery/misc-settings/#email-rate-limiting).

 

## The "Outgoing email is failing" warning

 

CRM-NG watches for failed sends. When emails keep failing, a red bar appears across CRM-NG screens:

 

> **Outgoing email is failing.:** It counts the emails that could not be sent and explains the impact: clients are not getting ticket updates, documents or account emails, and staff are not getting alerts.

 

Administrators see a link to fix the email settings; other staff are asked to tell an administrator. The setup step also flags *"Recent emails have been failing."*

 

To clear it:

 
1. Find the error
  Open **CRM-NG SMTP → Tools → Debug Events**, or the failed-send banner's **View Error Log**, and note the exact error.
2. Fix the cause
  Open the help article the banner links to, or follow [Troubleshooting email delivery](https://catalystgroup.gg/docs/email-delivery/troubleshooting/).
3. Send a test
  Go to **CRM-NG SMTP → Tools → Email Test**. When emails succeed again, the warning clears.

 

A common cause is an expired sign-in for an OAuth mailer such as Google. Reconnect the account on the **General** tab.

 

## Without CRM-NG

 

None of this is required. On a site without CRM-NG, CRM-NG SMTP simply sends all WordPress email through your chosen service.

 

## Related

 
- [Switching from another mail plugin (hand-over)](https://catalystgroup.gg/docs/email-delivery/switching-from-another-mail-plugin/)
- [Setting up CRM-NG SMTP in five minutes](https://catalystgroup.gg/docs/email-delivery/first-setup/)
- [Setting up the email log](https://catalystgroup.gg/docs/email-delivery/email-log-setup/)
- [Troubleshooting email delivery](https://catalystgroup.gg/docs/email-delivery/troubleshooting/)