PuTTY - Popular free terminal application. Mostly used as an SSH client.
MailChimp - MailChimp is the best way to design, send, and share email newsletters.
MobaXterm - Enhanced terminal for Windows with X11 server, tabbed SSH client, network tools and much more
Brevo - Innovative online Email Marketing solution to manage your contacts, create & send your newsletters and track your results. More than 80 000 clients. Best prices and attractive features.
iTerm2 - A terminal emulator for macOS that does amazing things.
Campaign Monitor - Email marketing software built for designers and their clients to run successful email campaigns.