Why are people viewing my e-mail in their browser? (Firefox)

[Anonymous]

Hi all,

I'm always interested in seeing how our e-mails are viewed in different platforms and thus I am curious as to why so many of the users who view our e-mail as a webpage have this user agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:27.0) Gecko/20100101 Firefox/27.0.

Does anyone have any idea of what e-mail client this is referring to? We test all our e-mails through Litmus to optimize performance and I'm wondering if there's a specific e-mail client that isn't seeing our e-mails correctly that we might not be testing for.

[Anonymous]

Claudia Aguirre​ FYI. I moved this to Products and Support​ so you can get an answer from the Community faster.

[SanfordWhiteman · Accepted solution]

No way to tell what client somebody is using based solely on the UA of their default browser.  All you know here is they're on Windows (making, say, Entourage/Apple Mail impossible and some version of Outlook likely).  If MUA info were leaked into the browser it would be pretty strange, right?

One thing you can do when you see people doing "View as Web Page" is perhaps send them a personal follow-up question about their email client ("We'd like to ensure compatibility"). All they have to do is reply and you can see their MUA, which is kind of neat. You could even be proactive and have "Need to view as Web Page? Tell us why" in every email.