Does hosting images locally on an ESP CMS improve email deliverability compared to external hosting like AWS?
Summary
What email marketers say10Marketer opinions
Email marketer from Mailgun explains that using a dedicated IP address for sending emails can improve deliverability, especially if the sender has a good reputation. While not directly related to image hosting, a good sending reputation is crucial, and factors like consistent sending volume and avoiding spam complaints play a significant role. Image hosting location is secondary to IP reputation and sending practices.
Email marketer from Email on Acid explains that optimizing images for email, including compressing file sizes and using appropriate dimensions, is crucial for user experience and can indirectly impact deliverability. Large images can lead to slow loading times and poor engagement, which could negatively affect sender reputation. Image hosting location isn't directly mentioned, but the focus is on overall email optimization.
Email marketer from Stack Overflow states that using a CDN for image hosting can improve loading times, which can indirectly affect user engagement and potentially sender reputation. Faster loading times can lead to a better user experience, potentially leading to higher engagement rates. This makes this a consideration for deliverability, but not a direct influencer
Email marketer from SendGrid shares that sender reputation is paramount for email deliverability. Factors like authentication (SPF, DKIM, DMARC), engagement, and list hygiene have a more substantial impact than where images are hosted. They suggest focusing on building a positive sender reputation through consistent, valuable email content, and proper email list management, rather than being overly concerned with image hosting location.
Email marketer from Hubspot explains how to maintain your email deliverability rates by using a familiar 'From' name, segmenting your emails, cleaning your email list, setting expectations, and by creating valuable and relevant content.
Email marketer from Reddit comments that, in their experience, the location of image hosting doesn't drastically affect deliverability as long as the images are served over HTTPS and the domain has a good reputation. They prioritize optimizing image size and using descriptive alt text for accessibility.
Email marketer from Litmus focuses on the importance of email authentication (SPF, DKIM, DMARC) and sender reputation for deliverability. They advise that these factors are more important than image hosting. Following email best practices has the most significant impact.
Email marketer from Email Geeks suggests not redirecting, but just linking directly as some filters interpret redirection as obfuscation of the final destination and will penalize for that. Due diligence is always a good idea so do check that the instance doesn’t get flagged. I think it’s no more likely to have problems flagged by filters than any other URLs in your email.
Email marketer from Email Geeks shares that as long as the IP isn’t in a known-abusive network, it’s probably not going to make much of a difference at most providers. It’s likely the impression came from the understanding that if it’s your own IP you don’t have to worry about your hosting provider letting another customer ruin that IP’s reputation without you knowing. Same goes for domains, regarding redirecting URIs through your domain to S3/whatever.
Email marketer from ActiveCampaign covers email best practices for deliverability that covers authentication, list health, and engagement are more important than image host locations.
What the experts say3Expert opinions
Expert from Word to the Wise focuses on sender reputation, authentication, and engagement as critical factors for deliverability. They do not directly address image hosting. The advice is to focus on building a trustworthy sending reputation, rather than worrying about minor factors.
Expert from Spam Resource indicates that factors such as authentication (SPF, DKIM, DMARC), sender reputation, and list hygiene are far more influential on deliverability than image hosting location. They emphasize that a good sending reputation and proper email practices outweigh the specific choice of image hosting.
Expert from Email Geeks explains that it mostly depends on the domain name involved. If you’re using the AWS domain name, yes, absolutely, that will affect delivery. If you’re using your own, it will affect it less. However, I have seen a few problems with an ESP client, where their S3 bucket (even behind their own domain) contained malware and viruses and problematic stuff for Reasons(tm) and that hurt their delivery.
What the documentation says4Technical articles
Documentation from IETF explains that SPF records are critical for email authentication and can improve deliverability by verifying that the sender is authorized to send emails on behalf of a domain. This applies regardless of where images are hosted, but proper SPF configuration is essential for a healthy sender reputation.
Documentation from DKIM explains that DKIM records are critical for email authentication and can improve deliverability by verifying that the sender is authorized to send emails on behalf of a domain. This applies regardless of where images are hosted, but proper DKIM configuration is essential for a healthy sender reputation.
Documentation from RFC explains that DMARC records are critical for email authentication and can improve deliverability by verifying that the sender is authorized to send emails on behalf of a domain. This applies regardless of where images are hosted, but proper DMARC configuration is essential for a healthy sender reputation.
Documentation from Amazon AWS shares security best practices for S3 buckets, including access control, encryption, and monitoring. Properly securing S3 buckets used for image hosting can prevent malware or unauthorized content from being served, which could negatively impact email deliverability if the domain is associated with spam or malicious activity.