Slack has something similar that shows above all channels. It makes it easy to browse through your unread messages without having to click each channel separately.

Our team documents project features by posting and re-editing posts. (They can then be flagged, or in future, made sticky, to keep them at hand.)

What would be useful here is to make a post that I choose to allow others to edit, in a wiki or confluence-style.

Our company would find it useful if there was an admin option to disable direct messages all-together.
We think this may help the work of teams where there is no need to discucc anything outside of team channels.

We have a Mattermost installation where I'm subscribed to 24 channels, most of which are fairly quiet. Except for the channels that are at the top and bottom of the list (of course). I'm continually scrolling up and down.

I'd like to have an option that hides channels that have no unread messages. Hiding all-read private groups and DMs would be a bonus.

The docs explains that:

"IP addresses, for example 10.100.200.101, do not return results."
(https://docs.mattermost.com/help/getting-started/searching.html#hashtags)

I would like to be able to search on ip-strings from my messages.

Mattermost has a manual Do Not Disturb feature, which is nice. However, it would be extra nice to have "Do Not Disturb hours" for each account, so individuals can set certain hours when Do Not Disturb is automatically enabled for their account. It would be extra nice if these were automatically set on account creation to common bedtime hours in the local time zone; for instance 10pm to 7am. This is a nice work/life balance feature that encourages people to get enough sleep by default. :-)

In addition to specifying custom data retention policy globally across all teams and channels (see https://mattermost.uservoice.com/forums/306457-general/suggestions/10007076-ee-data-retention-and-prune-reset-clear-channel-c), allow

1) team and system admins set custom policies for individual teams
2) channel, team and system admins set custom policies for individual channels

Hipchat to mattermost move API

Allow to reorder channels order (by drag n drop)

Add support for multiple lines in tables.
From: https://github.com/mattermost/platform/issues/1557

Add a keyboard shortcut to close the right hand sidebar (RHS) making it easier to exit replies and go back to the main channel.

If a user misses replying to a thread in a channel and instead replies directly to the channel, this message is not part of the thread that it was intended to be and the conversation is not clear.

There should be a way for a user or channel admin to move a message to the intended thread inside the channel and keep it inline with the on-going threaded conversation (since everything is timestamped this seems possible).

This would clean up the conversations and mistakes that users will make.

Mattermost seems to be a good candidate for making a Sandstorm app. Sandstorm https://sandstorm.io/ allows for secure bottling of web-apps. Many of the apps currently in the ecosystem are complementary to Mattermost - in function and ideology.

Currently the web interface has no option to increase the font size. This is plainly silly. Please fix this ASAP.

detect if user is really idle (away), not just if mattermost window doesn't has focus

Add badge for all unread non-mention messages to sidebar. Something like in skype. Actually it had already implimented, and would probably be merged into main release if a lot of people will be interest in this.
https://github.com/mattermost/platform/pull/2731

for the default search backend (sql), search results are capped at 100!

you can verify this by loading jquery and doing:

$('.search-item__container').length;

you can see that paging isn't supported:

https://github.com/mattermost/mattermost-server/blob/master/app/post.go#L821

and the sql uses LIMIT 100:

https://github.com/mattermost/mattermost-server/blob/master/store/sqlstore/post_store.go#L834

i know this isn't an issue in enterprise because you're using elasticsearch, but please either bring elasticsearch to team edition or fix the default search backend. 100 results is sad :(

Gravatar support to autopopulate avatar images

It would be nice to have an option, that enables the user to hide contacts that are currently offline.
This would mainly apply to the "direct messages".
It is really annoying to search through a long list (~50) of contacts you often need to chat with, when about 50% are currently offline and are therefore of no interest at the moment.