First, Install rbenv git clone https://github.com/rbenv/rbenv.git ~/.rbenv Add the following to your .bashrc or .zshrc export PATH="$HOME/.rbenv/bin:$PATH" eval "$(rbenv init -)" export PATH="$HOME/.rbenv/plugins/ruby-build/bin:$PATH" Run source ~/.zshrc or source ~/.bashrc git clone https://github.com/rbenv/ruby-build.git ~/.rbenv/plugins/ruby-build rbenv install -l Should list versions available to install rbenv install 2.3.1 && rbenv global 2.3.1 ruby -v Second, Install Mailcatcher sudo gem install mailcatcher vim /etc/systemd/system/mailcatcher.service Paste in: [Unit] Description=Ruby MailCatcher Documentation=http://mailcatcher.me/ [Service] # Ubuntu/Debian convention: Type=simple ExecStart=/home/vagrant/.rbenv/shims/mailcatcher --foreground --http-ip=192.168.10.18 [Install] WantedBy=multi-user.target Run systemctl enable mailcatcher.service, enter password when asked Restart vagrant and try going to 192.168.10.18:1080