Several factors can contribute to slower delivery times. Key reasons include:
High Volume Sending: Sending a large number of emails at once can overwhelm servers, resulting in a throttled delivery process. Email Service Provider (ESP) Policies: Some ESPs have specific policies to prevent spam, which may include limiting the rate of email sending. Recipient Server Delays: The recipient's email server may be experiencing high traffic or technical difficulties, causing delays. Content Filtering: Emails with certain content might be flagged for additional scrutiny, leading to slower delivery.