[toomim]

Noooooo...

The reason I switched to thunderbird is that it displays each email on a single line, which is sooooo much more information dense, and thus efficient! There's no better way to manage a large amount of email than displaying a large amount on screen!

[seraphine]

Even if they add it, the single-line display will always be around. It isn't mutually exclusive by any means. All clients that support multiline also have single-line support.

[toomim]

Nope. Mail.app removed it long ago. iOS mail has never had it. Even gmail is less info-dense than it could be, as it routinely increases the padding and margins for each message, even with the most dense view.