Why are my emails delayed even with a good reputation and no errors?
Summary
What email marketers say9Marketer opinions
Email marketer from Email Geeks mentions that delayed email delivery could be a result of DKIM replay, although more information is needed to confirm.
Email marketer from EmailGeek Forum shares that internal delays within the receiving organization (especially with large companies) can cause perceived delivery delays, even if the email was technically accepted quickly by the receiving server.
Email marketer from SparkPost explains that even with a good sender reputation, temporary deliverability issues can occur. These issues can stem from sudden spikes in sending volume or changes in sending patterns, triggering scrutiny from ISPs.
Email marketer from Mailjet explains that even with a good sender reputation, emails can be delayed due to factors like greylisting by receiving servers, which temporarily rejects emails from unknown senders. They suggest monitoring bounce logs and engaging with recipients to improve engagement metrics.
Email marketer from SendGrid explains that factors like recipient engagement (opens, clicks, replies) play a crucial role in deliverability. Low engagement rates can lead to throttling and delays, even if the sender's domain reputation is good.
Email marketer from Email Geeks suggests that the user might be experiencing deferrals and recommends checking bounce logs for temporary and permanent rejections.
Email marketer from Litmus suggests that personalized email content may trigger email delays as spam filters can take longer to scan individual email messages. They suggest testing different content types to check what affect the email.
Email marketer from Reddit suggests that delays can sometimes be attributed to the recipient's email client or service provider throttling incoming messages to manage server load or prevent abuse. This is especially common with free email services.
Email marketer from StackOverflow notes that some SMTP servers intentionally introduce delays as a form of spam protection. This is more common with smaller email providers and can affect delivery times, particularly for bulk emails.
What the experts say1Expert opinion
Expert from Word to the Wise shares that delays can result from emails being deferred and held by recipient servers that may be performing additional security checks. She suggests checking your sending practices to identify any changes that may have triggered this behavior.
What the documentation says5Technical articles
Documentation from Google explains that Gmail can delay emails due to spam filtering processes, security checks, and prioritization algorithms. Emails from new or infrequent senders may experience longer delays while Gmail assesses their legitimacy.
Documentation from Cisco highlights that IronPort appliances, commonly used in enterprise environments, employ sophisticated spam filtering and reputation analysis that can introduce delays as emails are scanned and processed.
Documentation from VadeSecure describes how greylisting works as a spam-fighting technique where legitimate emails will be delivered after a delay, while many spam emails will be dropped by the sending server without retrying.
Documentation from RFC 5321 details that SMTP servers might delay message acceptance or delivery due to temporary network issues, server overload, or greylisting. It's standard practice for sending servers to retry delivery for a certain period.
Documentation from Microsoft explains that delays in Exchange Online can be caused by transport rules, anti-spam filtering, or server-side processing. Message tracking logs can provide detailed information about the path and processing time of emails.