Copper might be a bit more popular than Unlayer. We know about 1 link to it since March 2021 and only 1 link to Unlayer. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.
Before that we had some luck using RazorLight, but we did all email templates in an editor Unlayer, exported the html and made a layout and view files. Source: about 1 year ago
I've seen Copper CRM work quite well for contractors (assuming that your team is using or open to using Google Workspace - if you're not using Google Workspace, I'd probably ask why not? But then recommend you to use Pipedrive if you're not willing to switch to Google Workspace). Source: over 1 year ago
MJML - The open source framework for responsive emails
Zoho CRM - Omnichannel CRM for Businesses of all sizes
Stripo - Stripo is an all-in-one email design platform. We enable our clients to build emails of any complexity, including interactive AMP emails, really fast and easy.
Pipedrive - Sales pipeline software that gets you organized. Helps you focus on the right deals, so easy to use that salespeople just love it. Great for small teams.
BeeFree.io - Bee is MailUp's drag-&-drop editor for responsive design emails.
Freshsales CRM - A full-fledged CRM for high-velocity sales teams.