Spam checkers analyze various components of your email, including:
1. Content: This includes your subject line, body text, and any multimedia elements. Certain words and phrases can trigger spam filters. 2. Format: This involves checking the use of HTML, images, and links. Emails with excessive images or poor formatting may be flagged. 3. Sender Reputation: The reputation of your sending domain and IP address can impact whether your email is considered spam. 4. Authentication: Ensuring that your emails are authenticated by DKIM, SPF, and DMARC can improve deliverability.