Add backports to your sources.list

Backports are recompiled packages from testing (mostly) and unstable (in a few cases only, e.g. security updates) in a stable environment so that they will run without new libraries (whenever it is possible) on a Debian stable distribution

Backports cannot be tested as extensively as Debian stable, and backports are provided on an as-is basis, with risk of incompatibilities with other components in Debian stable. Use with care!

It is therefore recommended to select single backported packages that fit your needs, and not use all available backports.

  1. touch /etc/apt/sources.list.d/backports.list
  2. nano /etc/apt/sources.list.d/backports.list
  3. Add the following line and then save it:
    deb http://deb.debian.org/debian buster-backports main
  4. apt-get update
  5. apt-get -t buster-backports install "package"

source: https://backports.debian.org/Instructions/

IMAPSYNC for Debian 9 installation

  1. apt-get update
  2. apt-get upgrade
  3. apt-install git libjson-webtoken-perl libauthen-ntlm-perl libcgi-pm-perl libcrypt-openssl-rsa-perl libdata-uniqid-perl libfile-copy-recursive-perl libio-socket-inet6-perl libio-socket-ssl-perl libio-tee-perl libhtml-parser-perl libjson-webtoken-perl libmail-imapclient-perl libparse-recdescent-perl libmodule-scandeps-perl libreadonly-perl libregexp-common-perl libsys-meminfo-perl libterm-readkey-perl libtest-mockobject-perl libtest-pod-perl libunicode-string-perl liburi-perl libwww-perl libtest-nowarnings-perl libtest-deep-perl libtest-warn-perl make cpanminus
  4. cd /home
  5. git clone https://github.com/imapsync/imapsync.git
  6. cd imapsync
  7. chmod +x imapsync
  8. Test it by typing
    ./imapsync
  9. You may need to install some extras by entering
    cpanm File::Tail
  10. cp imapsync /usr/bin/

Done!

Item 10 is to make sure you can use this command anywhere on the server. Have fun!