Preventing emails sent by BUSY (or any other application) from going to spam folders depends on several factors, including the email service provider, email content, and your email authentication settings. Here are some steps you can take to minimize the chances of emails from BUSY being marked as spam:
Step 1 : If possible, use a custom domain for your email sending. Emails sent from custom domains are often more trusted than those from generic domains like Gmail or Yahoo.
Step 2 :Avoid spammy content: Ensure that the content of your emails is not overly promotional, includes proper formatting, and avoids excessive use of spammy keywords.
Use a balanced mix of text and images: Emails that are primarily images can trigger spam filters. Balance images with text.