# Multi-window support and a better compose experience

DevFeed: [Multi-window support and a better compose experience](<https://devfeed.tech/articles/multi-window-support-and-a-better-compose-experience-51571.md>)

Original publisher: [Read original article](<https://www.fastmail.com/blog/multi-window-support/>)

Author: Neil Jenkins

Published: 2026-03-05T00:00:01Z

Content type: release

Language: en

Sources: [Fastmail Blog](<https://devfeed.tech/sources/fastmail-blog.md>)

Topics: [email](<https://devfeed.tech/topics/email.md>), [interface](<https://devfeed.tech/topics/interface.md>), [Mobile](<https://devfeed.tech/topics/mobile.md>), [screen](<https://devfeed.tech/topics/screen.md>), [Toolbar](<https://devfeed.tech/topics/toolbar.md>), [formatting](<https://devfeed.tech/topics/formatting.md>)

Tags: [desktop](<https://devfeed.tech/tags/desktop.md>), [drag-and-drop](<https://devfeed.tech/tags/drag-and-drop.md>), [email](<https://devfeed.tech/tags/email.md>), [formatting](<https://devfeed.tech/tags/formatting.md>), [interface](<https://devfeed.tech/tags/interface.md>), [productivity-tips](<https://devfeed.tech/tags/productivity-tips.md>), [screen](<https://devfeed.tech/tags/screen.md>), [toolbar](<https://devfeed.tech/tags/toolbar.md>), [update](<https://devfeed.tech/tags/update.md>), [window](<https://devfeed.tech/tags/window.md>)

## AI overview

Fastmail released an interface update focused on multitasking and composing email. It adds multi-window compose and conversation views, inline replies, a unified compose experience across mobile and desktop, flexible reply modes, toolbar controls, and drag-and-drop recipient management.

## Source excerpt

Today we're releasing a major update to the Fastmail interface, with improvements focused on making mulitasking and compose better. Here's what's new. Multi-window support Sometimes you need to reference one email while replying to another, or draft several messages at once. Fastmail now supports opening compose and conversation views in separate windows. Hold Shift when clicking reply, forward, or any compose action to open it in a new window. You can also use Shift+R to reply in a new window, or Shift+A to reply all. Or pop out a whole conversation into its own window by shift-clicking in the message list, or using the button next to the subject in the top right if it's already open. Your undo send timer works across windows too -- if you send from a pop-out window, the undo notification appears in your main window so you're still in control. Inline replies Replying to a message in a conversation now keeps you right where you are. Instead of switching to a separate compose screen, your reply appears inline within the thread, so you can see the full conversation while you write. It's the most natural way to reply -- you stay in context, and your draft lives alongside the messages you're responding to. If you'd rather compose in a focused view like before, you can expand your reply to full screen at any time. We'll remember your preference. A cleaner compose We've unified the look of our compose view across mobile and desktop, giving you a cleaner, more consistent interface wherever you're writing. A few highlights: Switch between Reply and Reply All mid-compose without losing your work. A new button in the compose header lets you change your reply mode on the fly, and Fastmail will intelligently recalculate the recipients for you. Hide the formatting toolbar if you prefer a distraction-free writing area. A toggle in the toolbar lets you show or hide formatting options with a single click, and your preference is remembered. Drag and drop recipients between To, Cc, and