How do I clear all tasks queued in the Magento Cron, specifically emails?

Question

I inherited a Magento project from the previous developer, and the Cron is broken on that server, so no transactional emails are being sent. There are 3-4 months of backed up emails that never sent; if I nuke the old server and migrate to a new instance then it will send 3 months of backed up confirmation and shipping emails. How can I clear all these without sending the emails? The cron_schedule table only has 26 records in it as of right now, all from orders placed today. As I monitor it the records in the table go up and down between about 20 to 30.

Is there any way I can clear all the cron tasks, so when I migrate the project to a new instance I won't spam all our customers with old emails?

Magento 1.9.2.3

Answer 1

There are a few things you can do.

The first thing is to clear the email queue table. The is stored in the core_email_queue table so truncating this table should clear the backlog of emails along with the core_email_queue_recipients table.

You can also disable emails being sent in the Magento admin in System -> Configuration -> Advanced -> System -> Mail Send Settings -> Disable Email Communications and setting this to yes and clearing the relevant caches and then run the CRON and switch it back afterwards to "No".

I would test this locally with one email order to be certain but those 2 things above should clear the email queue for you and prevent any backlog emails being sent to customers (though will also prevent any emails being sent to new orders).