1. Lack of Targeting: Sending generic emails to a broad audience without segmentation. 2. Irrelevant Content: Content that does not resonate with the recipient’s interests or needs. 3. Bad Timing: Sending emails at inappropriate times when the recipient is unlikely to engage. 4. Poor Design: Emails that are not mobile-friendly or have a cluttered layout. 5. Lack of Personalization: Failing to address recipients by their names or customize the content.