A subdomain is an additional part of your main domain name, separated by a dot. For example, in "newsletter.company.com," "newsletter" is the subdomain. Using a subdomain can be advantageous for email marketing because it helps you:
Segment Campaigns: Separate different types of email campaigns (e.g., promotional, transactional). Protect Main Domain: Shield your primary domain's reputation by isolating potential issues on the subdomain. Track Performance: Easily track and analyze the performance of specific email campaigns.