Developing emails alot of times can be like a time machine taking you back to the mid 2000s. Supporting the many Outlook versions that use IE and Word to render emails to Gmail, which has its own quirks, it can be a big pain. I have a Gulp setup that I found in a recent email campaign development that worked well for me.
It has live reload, will compile out a SASS file, inline the CSS, and it works with webfonts. For the webfonts, I found the css inlining was stripping them out, so I’m replacing a string (%FONT-FACE%) with a HTML file content that contains the webfont information.