[v16] Change subject + Speed improvements ⚡

Today we're releasing a handful feature and some speed improvements in Drag.

Just like in traditional Gmail, when replying to an email, you can now use the dropdown menu next to the email recipient field to change the subject line of that email.

Changing the email subject will generate a new email thread (and their respective card on Drag), just like in normal Gmail too.

We have been working on a series of speed improvements across Drag based on feedback from our users. These are just 2 of the many improvements we will announce over the coming weeks:

Faster "Send & Close" experience.

Faster loading of the compose box when replying to emails.