Webhook integration doesn't send @all messages.

[ronyodil]

Your Rocket.Chat version: 0.37.1 (problem appeared in 0.36.0).

When trying to send message with @ALL tag I'm getting '{"success":false}'. Single-user tags and common messages work as before.
Changes to 'mention-all' permission does not help. (#3703)

$ curl -X POST --data-urlencode 'payload={"text":"@all: test"}' $WEBHOOKURL
{"success":false}
$ curl -X POST --data-urlencode 'payload={"text":" test"}' $WEBHOOKURL                                            {"success":true}

[Syirrus]

@MartinSchoeler make sure the permissions are correct (set in admin) for the user you are using the API with to send messages to everyone.

[ronyodil]

I'm using Rocket.Cat for that. He is in Bots group. Also tried to add him to admins, moderators and room owners groups. No luck.
'mention-all' set to allow for everyone.

[vrooze]

I get this too.
I've been through all of the process as far as I can trace and all mentions work except @all you simply get a response of :
{ "success": false }

The query is simple:
payload:{"text": "Alert test @all"}

I was originally using a custom user but like the OP, I shifted to rocket.cat. I have given the bot group permissions to mention-all and it made no difference.