I have just upgraded my 5.2
install of laravel to 5.3
and then to 5.4
following the official upgrading methods.
I am now tryin
It seems that the older $message->embed doesn't work nicely with Markdown emails. Like you mentioned in the comments it seems broken since 5.4
But you could just try it like this inside your markdown email:
This is your logo
![Some option text][logo]
[logo]: {{asset('/img/official_logo.png')}} "Logo"
Like shown here: https://github.com/adam-p/markdown-here/wiki/Markdown-Cheatsheet#images
Asset function reference: https://laravel.com/docs/5.4/helpers#method-asset