Less Annoying CRM's integration with Mailchimp has two elements: contact sync between LACRM groups and Mailchimp audiences, and logging of emails sent from Mailchimp on CRM contact records. Unfortunately, due to the way Mailchimp's webhooks are designed, the latter functionality has a bad habit of causing problems with the use of autoresponders in Mailchimp.
Please note: autoresponders are a legacy feature in Mailchimp and can no longer be created. Mailchimp’s newer automation features can be used to automate campaigns instead of autoresponders, and campaigns sent using the automation features will not be logged into LACRM. Mailchimp still supports legacy autoresponders or you can convert existing autoresponders to Mailchimp’s newer automation, and there's an article here that explains how to use legacy autoresponders or convert to the newer automation in Mailchimp.
If you have autoresponders set up in Mailchimp, each time Mailchimp sends out an email to anyone in a synced audience, Mailchimp tells LACRM that an email blast has been sent to that entire audience. For some users, this means lots and lots of extraneous Mailchimp entries on CRM contact records simply because another contact in the same audience received an automated email from Mailchimp.
Unfortunately, there's no way to solve this issue with autoresponders without totally disabling the campaign logging portion of the integration for particular Mailchimp audiences. You'll still be able to use the contact syncing portion, but your email campaigns will not be logged to the CRM. If you convert your existing autoresponders to the automation features, email campaigns will also not be logged to the CRM.
To disable this portion of the sync, go to your audience in Mailchimp and select "Settings" from the Manage Audience drop down menu on the right.
Under your audience's Settings, select Webhooks.
Select the Edit button to the right of your Less Annoying CRM webhook, and uncheck the option for "campaign sending." Make sure to click Update as well!
Once you've changed this setting, no campaigns you send to that audience in Mailchimp will be logged to the CRM. This includes both your actual campaigns and autoresponders. If you have other Mailchimp audiences that are also synced to the CRM but are not using autoresponders, you can leave the "campaign sending" option checked for those audiences to continue using the full functionality of the integration with those subscribers. If you need to use this setting universally, you'll need to change it within each of the audiences that you have synced to LACRM.