Regular email user agent strings

Question

Is there a list of regular user agent strings that email clients use when opening HTML emails?

I want to make pixel network error detection using PHP in an email campaign.

Answer 1

I think you will find that there is no easy way to distinguish between email applications that open an html email address. All desktop agents use a certain rendering mechanism that is already built into web browsers (Thunderbird uses Gecko, earlier versions of Outlook use Internet Explorer, Mail.App uses WebKit, etc.), which makes them almost indistinguishable from the browser itself.

In any case, from a programming point of view, it’s not even useful to be able to tell the difference, because even if you could tell which client is used, there is no way to use this with a PHP script.

Answer 2

UserAgentString.com, Thunderbird . , . - , , , .

, Scunliffe, , . , , !;)

Answer 3

HTML- .

<img src="www.yourserver.com/track?id=someHASH..."/>

, , , , ..

, , , ( / ).

Thus, respect that many users will never upload an image ... but if your site is “convincing / reliable enough,” the user can upload the image.

Also, understand that if the user redirects the email to other users or reopens the email later, this may cause the web-based “call home” error to light up again (depending on caching, etc.).