[Leica] Archival 4x6 Prints?

[rbaron at concentric.net (Robert D. Baron)]

I need to put some money where my mouth has been and get started
making (having made) a lot of 4x6 prints from digital images of family
members and get togethers to go in various shoe boxes around the
country to be saved and viewed by future generations.

I really don't want (or have the time and patience) to do the printing
myself on my Epson 2200 or 1270 inkjet printers, although I suppose I
could buy one of those dedicated snapshot printers for around $100 or
so.  Are such prints really expected to last?

I am thinking about burning the image files to a CD and taking it to a
local camera store, drug store or walmart for prints.  Or, I suppose I
could mail or email the files to someplace like Adorama in New York.

But I really don't understand the processes these places use.  I
assume it is some sort of inkjet printing but I don't know that and of
course the local counter clerks seem to have no idea.

In the olden days our family snaps were made with film and printed on
real photographic paper on a machine in a darkroom (I worked in such a
place in the fifties) and they have survived pretty well. Will
(should) current commercially made, reasonably priced prints stand the
test of time?

Your suggestions and advice will be much appreciated.

--Bob Baron / Oklahoma City