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.
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. That includes non-current models of BlackBerry, and other older mobile devices unable to view HTML email. As a result, these are not tracked and do not appear in your reports.
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.
Lotus Notes via Domino
Certain configurations of Lotus Notes, specifically more recent versions configured to retrieve email from a Domino server, appear identical to Outlook 2003. In these cases, Email Analytics will identify the Lotus Notes client as Outlook 2003, but it is worth noting that if a Lotus Notes client appears as Outlook 2003, that also means it will render identically to Outlook 2003. So if your email is compatible with Outlook 2003, it will be compatible with this particular configuration of Lotus Notes.
Entourage 2008, 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 Entourage 2004 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.
A similar issue applies to Lotus Notes 6.0 (only this specific version due to a bug that was later fixed), and Entourage 2004. These clients will record opens but not engagement.
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. We have disabled all tracking for the Lotus Notes 6 client due to a problem with this version of the Notes client requesting the tracking images hundreds of times for each subscriber open made. Additionally, we cannot identify Lotus Notes 7 or 8 opens. These versions of Notes do not send a unique user agent or referrer so they are not distinguishable from other clients.