Previous post contains a solution to the problem!
You need to install 'libssl1.0.0' и 'libzmq3' from 'Jessy' repositories.

WBR, Vladimir.

Repository list:
deb http://ftp.sk.debian.org/debian/ stable main contrib non-free
deb http://security.debian.org/ stable/updates main contrib non-free
deb http://ftp.sk.debian.org/debian/ stable-updates main contrib non-free
deb http://packages.netxms.org/debian jessie main

But it still end-ups here:
root@db2:~# apt-get install netxms-server
Reading package lists... Done
Building dependency tree     
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 netxms-server : Depends: libzmq3 (>= 4.0.1+dfsg) but it is not installable
E: Unable to correct problems, you have held broken packages.

root@db2:~# dpkg -l | grep libzmq
ii  libzmq3-dev:amd64              4.2.1-4                        amd64        lightweight messaging kernel (development files)
ii  libzmq5:amd64                  4.2.1-4                        amd64        lightweight messaging kernel (shared library)

"libssl1.0.0 from jessie"has been installed so it got me one step further..

Any help would be appreciate..

i needed to install libssl1.0.0 from jessie repositories and that solved the issue.

then i came accross this issue while initialising the data base

"Initializing database...
SQL query failed (Specified key was too long; max key length is 767 bytes)"

but i solved that by creating a utf8 database.

regards

Maciej

Verity sources, do apt update, also check for held packages (apt-mark showhold)

Sorry my mistake

its debian 9.1.0 (Stretch)

regards

Maciej

Debian 10 (which is sid) or 9 (Stretch)?