[yakshaving_jgt]

Yes, you can put them in there, but then you're relying on the recipient's client to turn that plaintext url into a link the recipient can actually click on, as opposed to having to copy and paste the url into their browser address bar.

Right? Or do I have something wrong?

[toast0]

Yeah, but most email clients do linkify urls in text/plain emails. Heck, an awful lot of email clients linkify urls in text/html emails.

[JimDabell]

All the mail clients I use support this, including URLs that wrap onto new lines. Yet I still receive some emails with broken links if they wrap onto new lines. Somewhere along the way, these break before getting to my mail client. I never experience this with HTML email.

If you send long URLs – for instance password reset links with tokens in them – then you need to send them with an HTML part if you want them to be as reliable as possible. Leaving long URLs at the mercy of not just mail clients but the entire mail transmission apparatus, cannot be relied upon.