Some mobile mail apps, including the W10 Mail app, do not format links correctly, to be clickable, when the link is typed in directly, instead of embedded in text, like this. These apps don't have a true plain text option. Some links are embedded in text but the http:// prefix is omitted.

You can sometimes detect the mail app or other formatting clues by viewing the message source (Ctrl+U).

So the CTRL-U shows this, which shows all kinds of terrible coding:

Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable

Hello allI made a posting on the website for karl trip if you want an easy = link to follow him click herehttp://w3kwh.com/2019/04/25/where-is-the-world= -is-wa3vxj/Sent from Samsung Galaxy smartphone.

Even if the sender had put a space between here and http, the link might not have worked. If you get a lot of mail from senders using phones or tablets, try to suggest they embed links in text to avoid unclickable and wrapping issues.