Limitations to email analytics
There are some known limitations to Litmus' Email Analytics. These are detailed below.
NOTE: To meet our privacy standards and for accuracy, Litmus no longer contains reliable forward or print data for any inbox provider.
Images disabled
Since we rely upon image loading, we aren't able to track recipients who do not enable images for your email. Email Analytics is a way to break down your open rate—to give you further insight into your recipients who did open your message. Some email clients block external images or are not capable of displaying HTML email.
Gmail, Yahoo! and AOL
Email accounts for these providers cache images for emails viewed on the web and on mobile apps. Image caching impacts the way Email Analytics can report webmail and mobile app opens. Because these three providers use proxy processes, Litmus reports these as image cache opens. Engagement is also masked by the providers' processes so these opens will be excluded from engagement reporting to provide the greatest accuracy possible.
Apple Mail Privacy Protection
Apple MPP impacts the way we can report opens. See this article for full details.
Outlook 2016 for Windows and newer versions
Outlook 2016 for Windows and the newer versions return the same identifiers, so we can’t distinguish between them. They are all labelled as Outlook 2016.
Outlook for Mac 2011 and 2016
Since Entourage 2008, Microsoft has begun embedding the Apple Mail (WebKit) rendering engine within their email client. As a result, these clients render identically and will appear under Apple Mail within Email Analytics.
Webmail, Other category opens, and engagement tracking
Web-based email clients (Gmail, Outlook.com, and Yahoo! Mail) use an asynchronous processing model that will continue to load an email even after you've closed it and moved on to another message in your inbox. As a result, we are unable to detect when the user stops viewing the email as we can in other clients. We exclude the engagement of Gmail, Outlook.com, Yahoo! Mail, and AOL Mail users from our engagement reports, to avoid reducing the accuracy of the report.
Clients categorized as Other cannot be tracked for engagement and will be excluded from the engagement report.
We are unable to reliably track Lotus Notes opens and engagement.
Email clients that we are unable to track engagement for will show as a read time of -1 in exports.