unknown thing that appears from time to time.

[GNV]

  What is this.  \uD83C\uDF43?  And why?  I see it in emails and is it just to be ignored?

Thanks

[AdminMan]

The technical explanation is that these are Unicode Java-escaped characters, in this case, falling leaves. See https://charbase.com/1f343-unicode-leaf-fluttering-in-wind .

If they appear in an email, they are most likely just some random characters that a spammer has inserted to defeat spam filters that rely on pattern matching. Other spammers use huge block of text swiped from Wikipedia pages to try and "hide" the one or two nasty URLs they have included.

If your ISP is using IMAP, you should be able to look at these same messages in your local computer/phone/tablet email client AND in the webmail client that most ISPs provide. If the odd character only appear on ONE of the devices, you may need to update or refresh your email client.

[GNV]

Thank you for the answer.  Seeing it in a bit of detail this way has made it more clear.