Thank you Mark and Steve
To clarify, Mark, I am posting by my email client (I am using the hosted version of MM3, which is only up to version 1.2.2. I don't see any formatting or uploading options.
I suspect in your case the issue is Filter content and Collapse alternatives are both Yes.
That is correct. Thank you. I have set them to NO.
About links looking different in Hyperkitty vs Mail Client, it seems it comes out truncated in Hyperkitty in at least one case, but the link works. I will take your suggestions nd just type the link, or add white space to avoid ambiguity, or use brackets < and >. Thanks for the appendix C reference: "... In practice, URIs are delimited in a variety of ways, but usually within double-quotes "http://example.com/", angle brackets <http://example.com/>, or just by using whitespace:"
Steve, taking a cue from your message about embedding, I tried to recreate the message using cut and paste from the website so that images (as well as URL) are embedded. (It seems to add a string to the mailing list's pass_types attribute, etc. I would need to have my own installation. I guess in that sense my issues reflect a user who uses a hosted version, as I did with Mailman 2.)
I would like to try to upload my embedded version in the next message to see if it works.
Thanks
paul