I'm feeling stupid here. This is a problem that has arisen since updating an earlier version of Tumbleweed (probably about a six month gap)

I can open kaddressbook and send an email to an address list (but only TO, not CC or BCC)
I can open kmail and select addresses from an addresslist one-by-one as BCC, CC, TO

However, I cannot auto populate one of the three fields (TO, CC, BCC) in kmail with an address list

This feels so basic (even squirrel mail does this) that I must be doing something wrong, However I cannot for the life of me identify what to do.

kmail/addressbook versions 5.4.3

Please help...