Allow plugins to add to the settings menu, much like they can add to the System Console settings.

It would be nice to be able to click/drag the sidebar (where channels are) and resize it/ hide it if desired.

Resizing it and having a channel name abbreviated with ... could make sense;

ex: Town Square once it starts getting cut off would become Tow... (depending on how small you make the sidebar). Then if you go over far enough it snaps into a hidden position

Currently you have to know and type the exact name when searching in a direct message history of a single person via "in:@name". Whatever you type is even falsely "corrected" to some other channel when there is a match and you hit enter!

That is why I suggest to include member names in the suggestions when typing a name with "in:@...".

Currently when using the channel reference (~ sign), it returns all public channels that matches the search, regardless of whether the user is a member of it or not.

It would be more efficient to only show channels that the user is currently a part of

Currently when using the channel reference (~ sign), it sorts the results alphabetically, and it matches these search results based on the display name, the channel URL and the channel purpose.

It would be better however if it were to sort the direct matches with display name higher/at the top of the list so it would be easier for users to find and navigate to those channels.

Notifications of new chat messages should not be emailed if the chat message has already been deleted.

See:
https://github.com/mattermost/mattermost-server/issues/13064

There should be a 'Buzz' to alert the other user. Like, Spark, Yahoo.

Sometimes we have messaged to another user. But user is busy on another task. He/She missed the messages which is very important.

In this case, the user should have a 'Buzz' button or shortcut for alert to someone. I hope everyone knows about the importance of 'Buzz'. :)

File upload should trigger a modal to be shown in which user can add more files and also enter corresponding text against the image upload.
I would like to help in implementing this feature.

In the current setup the mobile app is ignoring the custom markdown dimension parameters for images.

https://github.com/mattermost/mattermost-server/issues/12970

Instead of Amazon S3, being able to use MS OneDrive for media storage.

This would be great for companies who have this large amount of storage essentially 'free' with their Office 365 accounts rather than spending for S3 storage.

Please see the proposal this chat thread: https://community.mattermost.com/core/pl/bb376sjsdbym8kj7nz7zrcos7r

When a message is edited, there is currently no possibility to see, when it has been edited. Maybe add the datetime of edit to (edited) text

To have a single mattermost client connected to several teams is a great feature.

What i find missing is a keyboard shortcut to change team. The other shortcuts are very good and I usually can navigate through many channels and conversations with keyboard only, but when I see that have received in other team, I have to use the mouse.

Perhaps you could add tabs or something similar to the "quick channel switcher" (Ctrl-K) or have a new shortcut to switch teams (e.g. Ctrl-T).

Currently tons of space is being wasted in the sidebar. Allow for tighter spacing of channel/user names so more of the list can be displayed at once.

Add the ability to Collapse a post containing markup. Just like you can already do with a image.

Add the ability to exclude notification words.
Like this:
Words that trigger mentions: foo
Words that do not trigger mentions: foo-bar

Having bad admins that make errors during the creation of certificates is silly. However, not being able to override their silly mistakes while they fail to address the issue over the course of months is aggravating. Although the issue will be eventually addressed, every time I open up mattermost, I get an invalid certificate error which I have to manually dismiss. I would really like to dismiss this permanently so that I don't have to deal with the extra 3 clicks every time I open up the application.

Hello,

I am using Mattermost Android app to receive notification and messages. But it is very confusing to distinguish between other notification and Mattermost notification.

It takes the default notification tone of mobile and desktop.

Please provide the option to change the notification sound or if there is any method to do that then please let me know.

Add server plugin hooks for access control (permission change) and logout events to enable developers to create custom server plugins to integrate with internal auditing/intrusion detection tools.

https://developers.mattermost.com/extend/plugins/server/reference/#Hooks