Yes. A comment-to-DM automation can watch any post or reel on your account, however old. If a reel from last year still gets comments every day, it is one of the best places to put an automation.
What happens to comments made before setup
When you switch on an automation, it replies to new comments from that moment. Comments that were already there are not answered automatically. That is deliberate: you would not want everyone who commented over the past year to suddenly get a DM.
DM Flow marks existing comments as already handled the first time it watches a post, so only fresh comments get a DM.
The seven-day rule
Instagram allows a private reply to a comment for seven days after it was posted. If you want to reach people who commented in the last week before your automation started, reply to them yourself from the Instagram app.
Old posts worth automating
- Evergreen reels that keep getting comments ("what's the price?", "link?")
- Product posts still pinned to your profile
- Tutorials where people ask for the resource
- Old giveaway or launch posts that people still find through search
How to bring an old reel back
- Edit the caption to add: "Comment LINK and I'll DM you."
- Pin it to your profile.
- Share it to your story with the same call to action.
- Turn on the automation with keywords like
link,price,details.
Every post at once
If you have many old posts, use an every-post automation (paid plans in DM Flow) with a general keyword like link. Specific automations on individual posts still take priority.
Related reading
Frequently asked questions
Can I DM everyone who commented on an old post?
Not automatically, and only within seven days of each comment. Older commenters cannot be messaged through automation.
Does editing the caption reset anything?
No. Editing the caption is fine; the automation keeps watching the same post.
Do old posts need anything different?
No. Choose the post in the automation like any new one.