How Slack Decides to Send a Notification

Should we send a notification?

Thread message & User subscribed

Channel muted?

No

Yes

No

Yes

Legend

Pref

Pref Value

User State/Action

Parsing

User in Dnd?

Yes

No

DnD Override?

No

Yes

@channel/@everyone/@here message?

Yes

No

@channel mentions suppresed?

Yes

No

Channel notification pref is "Nothing"

threads_everything pref on?

Thread message & User subscribed?

Yes

Yes

Yes

No

No

No

What is the user's channel notification pref for this device?

What is the user's global notification pref for this device?

Nothing

Everything

Mentions

Default

No

DM?

@here

Highlight word?

All

Thread message?

@mention? Comment on file owned by user? (desktop)

Mentions

DMs (mobile)

Highlight Words (mobile)

Never

No

No

User presence active?

Yes

Thread message?

Yes

DM?

Yes

No

User subscribed?

No

Yes

No

User subscribed?

Yes

Yes

Thread message?

@mention? Highlight word?

No

NO

YES

Yes

No

Yes

User subscribed?

No

Past mobile push timing threshold?

NB: If the user's desktop client Mark as Read pref is set to Mark the channel read, mobile pushes will not be sent for messages marked read on the desktop (ie. when the user leaves their computer open to a channel).

Mobile?

Yes

Source: Slack Engineering