Propagation delays can occur due to multiple reasons, such as:
Server Load: High traffic on the email server can cause delays. Network Congestion: Heavy internet traffic can slow down email delivery. Spam Filters: Emails passing through spam filters may take longer to be delivered. Email Authentication: Processes like SPF, DKIM, and DMARC checks can add to the delay. Recipient's Server: The speed and configuration of the recipient’s email server can also affect delivery time.