I'm doing some fixes in a legacy system and it has an e-mail template which uses a lot of esd-something css classes. Examples: esd-footer-popover, esd-email-paddings,etc.
I even found some articles explaining how to build an e-mail template using these classes, but I haven't found anything explaining where they come from or even how they're used. Maybe I'm doing the wrong search.
Is it something related with the e-mail protocols?
Link to the articles: https://dev.to/hr21don/coding-an-html-email-template-from-scratch-4eeg and https://medium.com/stripo-email/part-2-advanced-version-of-the-email-template-adaptation-f7fb2da0f22a
This is from the Stripo email design system (email system design?).
They just prefix their classes so that it doesn't clash with other classes you may already have - this is a common technique so that multiple libraries or systems can work well with each other without clashing/overriding each other.