[alberth]

I love Fastmail (and am a paid user) … but don’t understand what problem this feature is solving.

[dolni]

Some use cases are described in the blog post.

I have wanted a feature like this before and worked around it by replying to the email but sending the reply only to me.

[callmeal]

an immediate one for me is to track notes from phone calls to support. My current process is to reply to the email with my notes from the call.

[slightwinder]

It's just another way of managing notes and tasks. Attaching notes and tasks directly to the mail, can result in shorter workflows. I mean, information should be where it's used, and mails are a very central point of some peoples' life.