Clarification needed for access to package versions in repositories

[Bret Busby]

Hello.

I am running Linux Mint Mate 21.3 on two of my computers. This relates 
to my primary computer.

What started as another user's problem with the person's computer going 
like a runaway train with automated upgrades, against the wishes of the 
user, resulting in unwanted changes occurring with Claws Mail, that the 
person uses as a primary email application, led to other problems.

The other person, in running Linux Mint Cinnamon 21,3, has Claws Mail 
4.1.1, whereas I have 4.0.0, and, the other person is running kernel 
version 6.5.0, whereas I am running kernel version 5.15.0.

So, I posted the output of
cat /etc/apt/sources.list.d/official-packages-repositories.list
;

"
 > cat /etc/apt/sources.list.d/official-package-repositories.list
deb http://packages.linuxmint.com virginia main upstream import backport 
#id:linuxmint_main

deb http://archive.ubuntu.com/ubuntu jammy main restricted universe 
multiverse
deb http://archive.ubuntu.com/ubuntu jammy-updates main restricted 
universe multiverse
deb http://archive.ubuntu.com/ubuntu jammy-backports main restricted 
universe multiverse

deb http://security.ubuntu.com/ubuntu/ jammy-security main restricted 
universe multiverse
"

and asked for the other person to do the same.

The response to that part of the reply that I got from the person, is

"
1) I copied and pasted the line you gave me into the terminal but the
result was "No such file or directory."   :o(

2) So I opened the file, copied, and pasted it here for you:

deb http://packages.linuxmint.com virginia main upstream import
backport

deb http://ftp.usf.edu/pub/ubuntu jammy main restricted universe
multiverse deb http://ftp.usf.edu/pub/ubuntu jammy-updates main
restricted universe multiverse deb http://ftp.usf.edu/pub/ubuntu
jammy-backports main restricted universe multiverse

deb http://security.ubuntu.com/ubuntu/ jammy-security main restricted
universe multiverse

3) What does this tell you?
"

So, I am wondering why, on two installations of Linux Mint 21.3, whilst 
I can get a response to
  cat /etc/apt/sources.list.d/official-package-repositories.list
the other person gets the error message shown; is it that the Cinnamon 
version would store the list of official package sources, differently to 
the Mate version, or, would the Cinnamon version not include the cat 
utility in its base installation?

Then, arises the question - as the other person's Ubuntu repositories, 
at .usf.edu/pub, are at a different location to mine ( 
archive.ubuntu.com), in wondering whether the two different repository 
locations, have different versions of packages, with the usf edu one, 
apparently, having significantly later versions, than the Ubuntu one, is 
a quick and simple method available, to find the version numbers of 
packages, in the usf.edu repository?  I tried to look, and, it is like 
Dune - "plans within plans", with no apparent quick and easy way to find 
included packages and their version numbers.

The version numbers of the packages that I have installed (the kernel, 
and Claws Mail), are shown by synaptic, to be the latest available 
versions, in the Ubuntu repository.

....
Bret Busby
Armadale
Western Australia
(UTC+0800)
.................