There are a few pieces that you need to manage your own mail server.
This snap makes the process easy, it will setup most things that
you expect from a mail server. Because the process is automated and
easy expect the installation to be somewhat unflexible.
For versions of Ubuntu between 14.04 LTS (Trusty Tahr) and 15.10 (Wily Werewolf), as well as Ubuntu flavours that don’t include snap by default, snap can be installed from the Ubuntu Software Centre by searching for snapd.
Alternatively, snapd can be installed from the command line:
sudo apt update
sudo apt install snapd
Either log out and back in again, or restart your system, to ensure snap’s paths are updated correctly.
To install Parcel, simply use the following command: