Delivery issues can severely impact your email marketing efforts. To investigate, start by:
Checking your sender reputation. Tools like Sender Score can help you gauge your reputation. Ensuring that your email list is clean and up-to-date. Remove invalid and inactive email addresses regularly. Reviewing your email authentication settings. Implementing SPF, DKIM, and DMARC can improve your deliverability. Monitoring your emails for spam trigger words and excessive use of images, which can land your emails in the spam folder.