Option to optimize the spell check and grammar tool, for extensive editing while composing emails in Outlook 2016. Also bring back “look up” in the drop down menu that comes up when you right click. If you choose “look up” in the past, you’d be linked to a dictionary. Now there is just the “Thesaurus” option and provide a spell check option when an email is in capital letters in Microsoft Outlook 2016. Also Spellcheck should automatically know that words which match the spelling of a name in an email address in the ‘To:’ or ‘Cc:’ fields are not spelled incorrectly. I think it would be very useful for software developers if an option is added to the settings to check every word individually in regards to camelCase and PascalCase.

So many of us are dedicated users of Outlook for Windows... and also use a Win10 Mobile phone.
Problem: each device uses a different calendar: Office for Windows uses my default email ID, which is my domain email ID (not Exchange). The phone uses an Outlook.com email ID. To get a calendar item sent over to the phone, I have to manually copy all of my calendar items in Outlook for Windows over to the Outlook.com calendar under "My Calendars". Interoperability between the two platforms is difficult.
Solution: We need an option in Outlook for Windows to change the default calendar to the Outlook.com calendar - without having to change the default email ID. Exchange cannot be part of the solution, we are using Outlook.com as the intermediary between the two devices.

The rules and alerts are powerful and very important in properly organizing Microsoft Outlook inbox. However it has been observed:

The User Interface is old. The dialog cannot be re-sized and managing many rules becomes tedious.

All the rules are not compatible between web version and desktop client even when the features are available on both. While not having some sounds or special events on the web version can be understandable, not being able to categorize the emails is annoying. It would be nice to have some "cleanup features" to review the rules. Also Creation of rules to automatic categorization events would be an added benefit.

We would love to see some improvements there like "Move after I read" emails in Outlook 2016.

New feature request: Introduce email locking mechanism to prevent multiple email threads of the same subject.

Problem:

Sometimes, at workplace in the same group, multiple people will be replying all to the same email thread. As a result, there will be several threads of the same email floating around. Different people’s emails will be in different threads of the same email subject.

Proposal:
1.Introduce a button in the compose email window that says, “Lock”.
2.Whenever someone (say, Person A) is replying all to an email message, he/she clicks on the “Lock” button.
3.At the email server, there would be a queue for locked messages.
4.Another person, say, Person B, also tries to reply-all to the same email message. He/she clicks on “Lock” button.
5.The email server sees that there is already a lock for the same email message and returns a warning to Person B that Person A is replying to the same email.
6.The lock will be released once Person A sends the email. Or, after a certain period (configurable at the server), say 10 minutes. Or, if Person A discards/deletes the email. Or, if Person A’s Outlook loses connection with the server.
7.The “lock” can be made automatic too. Like, when it is saved as draft, the “lock” can be automatically applied.
8.Locking would be limited to the emails within the same organization and will not be applicable for external emails.
9.Person B could still send the message ignoring the lock warning message. In that case, something in the email subject could indicate that emails will have to be manually merged.

Option to be able to pin or stick important emails at the top of your inbox regardless of the date and time they were received when sorted by date. Also consider this scenario: Option to be able to pin someone automatically when we reply or send new mail.

We PIN all the “must” people in the CC so it will save our time in putting all the people in the CC every time we send mail. Plus, since there are a lot of “must” people to be filled out in CC, there may be some mistake to not include some people. We would like to avoid such problem.

The clutter feature has been really frustrating to many people I know and work with. There seems to be a lack of understanding of how it works and that the clutter folder still needs to be monitored. Many people also believe that it acts just like the spam folder.

My suggestion would be to provide some in-app training. Upon login during the first week or so, provide a popup on the clutter folder that draws attention to emails it has cluttered:
'I moved 4 messages to clutter today. Please check them out. Or, if you would like me to stop automatically moving messages, click here to disable me.'

This training could also apply to future features that will be enabled by default.