Lower deliverability / higher spam rate after automating campaign creation

Hey folks,

Recently our company has automated bulk campaign scheduling with n8n and the deliverability has been impacted.

Just a few days before we automated this process, campaigns averaged 22% Open Rate, and 0.85% Click rate.

Now we are at 9% OR and 0.65% CR.

What remains the same from the process: senders, email content, accounts used, volume/frequency of emails, list of contacts

What changed: we are retrieving the templates preview content, and adding it to the message that we created with the campaign. Before, we duplicated a previous campaign, edited the content and scheduled it manually all inside ActiveCampaign.

These are the endpoints we are using, in order:

1. Create Message (API v3): /api/3/messages
2. Create Campaign (API v1): /admin/api.php?api_action=campaign_create
3. Retrieve Template (API v3): /api/3/template
4. Update Message (API v3): /api/3/messages/
5. Send Test Email (API v3): /admin/api.php?api_action=campaign_send

Would appreciate your help, as with such a high spam rate, we can't keep using the automation we created.