How to schedule Slack Messages
- Add PostDelegate to Slack. On the calendar page choose Add Channel, then Slack. Choose the workspace and allow PostDelegate. It asks to see the workspace's channels and members, join public channels and post messages. You need to be allowed to add apps to the workspace.
- Write the message. Choose Create Post and select the Slack workspace. Write the message with Slack's formatting and add PNG, JPG or GIF images if you like.
- Pick the Slack channel. Choose the Slack channel to post to. PostDelegate joins a public channel on its own before posting.
- Schedule it. Pick a date and time and choose Add to Calendar. Add more entries to send follow-ups as thread replies.
What you can publish to Slack
Slack is a workplace chat app, and scheduled messages are useful for announcements, reminders and updates that should land at a set time. PostDelegate sends each post as a message to the channel you choose, and text uses Slack's own formatting.
Messages appear from the PostDelegate app, not from your own Slack account. Add images as PNG, JPG or GIF. Video is not supported. Follow-up entries in a post are sent as replies in a thread under the first message.
- Add PostDelegate to a workspace from Add Channel.
- Write a message and choose the Slack channel it goes to.
- Add follow-up entries to send replies in a thread.
Slack post settings
| Setting | Notes |
|---|---|
| Channel | Required. Choose the Slack channel to post to. PostDelegate joins a public channel on its own before posting. |
Before connecting
- PostDelegate cannot join private channels by itself. Invite the PostDelegate app to the channel in Slack, then pick it again.
- Messages are sent from the PostDelegate app, not your own Slack account.
Read the Slack guide in our documentation for connection steps, post settings and troubleshooting.
Plan Slack with the rest of your channels
Slack sits on the same calendar as every other channel you connect. In one post you can pick several channels, write the content once and adjust it for each, and every channel keeps its own settings. Save a draft to review a post first, choose Add to Calendar to schedule it, or choose Post now to send it immediately. The scheduling guide covers drafts, repeats, previews and time slots.
Use Claude or ChatGPT with Slack
PostDelegate runs an MCP server, so an assistant you already use can look at your Slack channel, read its rules and create a draft for you to review. AI is bring-your-own, and PostDelegate never charges for it. Setup guides: Claude, ChatGPT, and what a social media MCP server is.
Review the whole post
Check the destination, wording, media and time before scheduling. Look at the result in your workspace after publication; a queued item is not a published-post confirmation.