Following over a year of public testing, Microsoft released the new Outlook for Windows last week as a replacement for the Windows 10-era Mail and Calendar apps. It's supposed to eventually replace the regular Outlook client (from Microsoft Office/365), but there are a lot of features still missing before that can happen. Microsoft has now provided information on the features coming to the new Outlook over the next few months.

The new Outlook for Windows is a completely different codebase (the Outlook.com web app) than the classic Outlook client (a Win32 application) or the old Windows Mail and Calendar apps (UWP apps), so most features in the new Outlook have to be written from scratch. For example, IMAP support wasn't available until a few months into the testing period earlier this year, and some crucial features from classic Outlook and Mail are still missing.

Microsoft has updated its official Microsoft 365 Roadmap, revealing which features are coming soon to the new Outlook, including a few changes coming as soon as October. The most significant change is offline support, which is slated for October 2023. You'll be able to view your downloaded mail, calendar events, and contacts even when you don't have an internet connection, as well as write messages to send when your network connection comes back. It's a bit surprising that wasn't in the final public release, but at least it's coming soon.

Microsoft has also confirmed that ICS file support is on the way, with an estimated release date of October. Calendar events are often distributed in emails and websites as ICS files, and opening them in classic Outlook, Apple Calendar on Mac, and other apps will add them to your own calendar. Microsoft says the feature in new Outlook "mimics the experience currently available in classic Outlook for Windows."

Farther out in the future, Microsoft is working on a setting for removing declined meetings from the calendar, which is planned to arrive in November 2023. There are no firm timelines for features beyond that, but Microsoft did say in a blog post earlier this month that folder reordering is in development, and the company is "investigating" POP support. The classic Outlook's COM add-ins will not be ported to the new experience — Microsoft is instead asking developers to create web add-ins, which are also compatible with the Outlook.com web app.

Source: Microsoft 365 Roadmap, Outlook Blog