Anyone know how to modify the spacer element to do something like this image?
Probably not possible with pure CSS and the limited CSS support in emails. An image might make more sense.
I know you can because I did it for a bunch of campaigns back in 2016.
Just deleted it.
I was also able to get this rough proof of concept working using mjml.
The biggest problem is going to be the angles because :after and :before aren’t widely supported.
The example I did back in 2016 used
<hr> though and this uses tables.
In the screen of the first post it looks like the end are less wide than the middle of the both sides.
So far spacer generates a simple cell with a fixed height. You may want to use the generated html markup from the mjml template if this works.
caniemail.com lists the supported CSS properties per email client.