What is the Newsletter Task Scheduler?
When you hit the send button, the plugin adds your email to what's called a "sending queue". The newsletter task scheduler monitors the sending queue and dispatches your email in batches to your subscribers.
The newsletter task scheduler is also responsible for ensuring that Post Notifications and Welcome Emails are processed and dispatched on time.
If you are using MailPoet's sending service, this process is very fast (50,000 emails per hour) and you are not limited by how many messages you can send per minute/hour/day. If you send with a sending method other than MailPoet, a sending frequency (e.g., X amount of emails delivered every Y minutes) is applied based on what's configured under Settings → Send with... tab. We recommend sticking to the safe recommended values.
Configuring the newsletter task scheduler
You can access it by going to the Settings → Advanced tab. There are 2 options:
- Visitors to your website (default): every visit (page load) to your website starts the task scheduler that temporarily runs in the background until all emails are processed.
- MailPoet's own script: the task scheduler runs as a non-stop background process and does not depend on site visitors or require an external source to start. While this method is very accurate and fast, it uses minimal server resources on a constant basis and may not be compatible with certain hosting providers (the list is not exhaustive) that place restrictions on running background processes.
Things to consider:
- If your hosting provider restricts daily/weekly CPU usage, we suggest that you select "Visitors to your website"
- If you don't schedule your emails and send them upon creation, we recommend option "Visitors to your website"
- If your site does not receive much traffic (e.g., 10 or fewer visitors per hour) and you need your emails to be sent exactly when scheduled, we recommend that you select option "MailPoet's own script"
- If you run a high traffic web site (e.g., 10+ visitors per minute, which may include crawlers/bots), option "Visitors to your website" may result in excessive database queries that could put a strain on the server, thus we recommend that you select option "MailPoet's own script"
You may wish to experiment with both methods to see which works best in your particular case. If sending does not work regardless of the chosen method, please read about diagnosing sending issues.