What are Mailchimp Queue Items?
Mailchimp Queue Items are internal records that Mailchimp for Salesforce creates when someone edits a Salesforce record that has mapped fields or email address changes relevant to Mailchimp. Rather than sending each individual edit to Mailchimp the moment it happens, the app stores these changes as Queue Item records and processes them asynchronously in small batches. This means your edits, like updating a mapped field value, changing an email address, or adjusting a subscription preference, are collected and then sent to Mailchimp in the background without slowing down your day-to-day work in Salesforce.
Queue Items are short-lived. Once the batch job picks them up and processes the change, the record has done its job and is no longer needed. If you see them in your recycle bin, that's completely normal.
A Note for Developers and Admins Familiar with Apex
The reason Queue Items exist comes down to a Salesforce platform constraint: sending data to an external service like Mailchimp requires an HTTP callout, and callouts cannot be made synchronously from certain contexts (like triggers). The standard practice in Salesforce is to hand off this kind of work to an asynchronous batch job, which runs in its own execution context where callouts are allowed.
These batch jobs don't always run instantly. Salesforce places asynchronous Apex jobs into a Flex Queue, which controls the order and timing of when they execute based on available platform resources. It's worth knowing that the Flex Queue is shared, so other installed apps and custom Apex in your org also compete for the same queue slots. If you notice Queue Items sitting for longer than expected, it may be because the Flex Queue is busy.
For more on how Salesforce manages asynchronous job execution, see Salesforce's documentation on the Apex Flex Queue and Monitoring the Apex Flex Queue.
