Email clients use different rendering standards. This is why your email can be displayed not as you designed it. You need to check that your message code won't cause rendering issues.
Vmail (Validate Email) check the markup (HTML, CSS) of HTML email template content in search of problematic elements. For each it finds, it displays the list of email clients that lack support for it or support it only partially.
VMail collect the data on support for particular HTML & CSS rules from Caniemail.com
To start it in development mode, you need install ruby, node.js, golang and run in terminal:
$ bundle # get all ruby deps
$ yarn # get all node.js deps
$ bundle exec rake wasm:parser # build wasm parser module
$ bundle exec rake wasm:inliner # build wasm inliner module
$ yarn dev # start server on 3000 port
$ bundle exec rake wasm:parser # build wasm parser module
$ bundle exec rake wasm:inliner # build wasm inliner module
yarn prettier --write --plugin-search-dir=. ./src/components/*
$ cd wasm_parser/parser
$ go test -benchmem -bench=.
git checkout -b my-new-feature
)git commit -am 'Add some feature'
)git push origin my-new-feature
)