Do you mean actual emails that you set as Text Only? If so, just select those emails in the report.
If you mean - how many people are getting the Text version, you cannot because it is not tracked separately.
I suspect if you did a search of % users of email clients you could get an idea of the possible proportion, say if people are using PINE vs. Outlook. Also depends on the audience - sysadmins prob use pine still.
I meant if I'm sending both HTML and text versions to everyone, what's the number of people who are only getting the text version due to their server settings.
I know you can't track opens, but back in the day with early email marketing tools you could see how many were getting the HTML version blocked, but I know much has changed.
It sounds like the 'delivered' quantity isn't trackable by Marketo, but I did find a thread where Marketo will put in a trackable link if you put double brackets around the link in the text email: [[www.example.com]].
If anyone knows how to track delivered text-only emails, would love to hear it.
@Brent E Reading the text version isn't about server setttings (unless you mean AD group policies which force apps on workstations to favor the text version). It's much more about client settings, like @Josh says about what kind of mail app they use. And also what settings are enforced within the mail client: in my mail app, for example, I used to set it to show the text version if one existed. I eventually buckled down and favor the HTML version now (but still do not automaticaly download images). Still the same app but you can't know that as a sender.
I don't know what you mean about early tools being able to tell you this. The only way that could be calculated is if you assumed that anyone that didn't load the tracking pixel must not have an app that is HTML-capable at all. That's obviously no longer true: I can see all HTML-enriched emails but I don't load the pixel unless I really like you.
The trackable [[link]] will work if someone clicks it, and if you vary the link in the text and HTML versions you'd get some insight. But that's leaving out everybody who read the text version and just didn't heed the CTA.
Thanks for the replies, folks. Much appreciated. One last question: so, it's not knowable (or directly knowable) what percent of your audience is receiving or choosing to receive the text version. That said, do any of you have a sense for what that percentage might be? My feeling is that it's well below 5%, perhaps even 1%, but I'm just not sure.