I finally figured out how to get Slack keyboard shortcuts to work...

Thanks Gemini!

This is one of the most confusing aspects of Slack because it violates the "standard" Mac behavior.

The short answer: "M" is a single-key shortcut, meaning it only works when your cursor is NOT in the text box.

If you are typing a message and press M, you just type the letter "m". For the shortcut to work, you must perform a "focus shift" first.

The "Two-Step Dance" to use the "M" Shortcut

To use the M key to set a reminder, you must first tell Slack, "I am not typing right now; I am looking at a message."

1. Step 1: Focus the Message List

   • Press F6 (or Fn + F6 depending on your Mac settings).

   • What happens: The blue (or grey) focus ring jumps from the text box to the message list above it.

   • Alternative: You can press the Up Arrow key until a message is highlighted in grey.

2. Step 2: Select the Message

   • Use the Up/Down Arrow keys to highlight the specific message you want to be reminded about.

3. Step 3: Press "M"

   • Now, press M on your keyboard.

   • What happens: The "Remind me about this" context menu will instantly pop up.

4. Step 4: Select Duration

   • Use your arrow keys to select a preset (e.g., "In 1 hour") or arrow down to "Custom..." and press Enter to type your specific duration (e.g., "Tuesday 9am").