There are multiple reasons for slow email delivery in email marketing. Some of the common causes include:
Server Load: High volumes of emails being sent simultaneously can overwhelm servers, causing delays. Spam Filters: Emails may be flagged by spam filters and held for review, delaying delivery. ISP Throttling: Internet Service Providers (ISPs) may limit the rate at which emails are accepted to prevent spam. Recipient's Email Server: The email server of the recipient may be experiencing issues, causing a delay. Technical Issues: Problems with the email service provider's infrastructure can also contribute to delays.