Response Detection is Not Working

Response Detection is a great way prevent unwanted followups. Here are some things to try if it’s is not working as expected.

Not Working At All

Are you on the right plan?
Make sure you are logged in, then navigate to our features page. Your current account level will be highlighted. Make sure you are a plan that supports this feature. (Note: If you already upgraded, you can link another email address to your already-upgraded account to enjoy the benefits on both)

Are you including -r in the date format?
(For example, indicates the followup will be canceled if a response has been received. If you would like response detection to be active on every followup, you can make use of our default options feature.

Are you inbox(es) connected?
After enabling response detection on the connected services page, did you then proceed to connect your email inboxes? The blue button next to your email changes from “Connect Inbox” to “Disconnect Inbox” when it is connected (note that alias addresses do not need to be connected, only the base inbox more).

Is your email coming from the right address?
Check the “from” address in your test email. Does this address correspond with one of the connected inboxes? If you don’t see it listed you can link that email address to your paid account.


Intermittently Working

Did you schedule more than one followup for the same / similar thread?
Response detection may have cancelled one followup, but left the other one active. To check, go to My Followups  filter by “completed” followups and search a few words in the subject. If there are multiple followups with the same subject, you’ve found the culprit. If this happens frequently, you may want to consider adding the “-c” option (ex: to auto-cancel other followups in the same thread.

Is One Inbox Connected But Not Another?
Note the “from” address on your various followups. Is response detection working when you send from one address but not another? You may need to head over to your connected services page to connect an additional inbox, or link your accounts.

There Are Edge Cases
FollowUpThen uses to integrate with your email inbox and notify us when a reply has been received.

Occasionally, is unable to detect a response. There are thousands of variations of email content, addresses and providers and not all systems work the same way. has done an amazing job accomodating these differences, but they are not perfect. Unfortunately, neither is your email provider.

This is especially important when using the ‘cc’ field (where your sender gets the followup, too).

Here are some things to look out for if response detection missed a reply.

Emails That Hide The Fact They Are Replies
For example, you send an email that goes into a helpdesk system (ex: The response may or may not reference itself as a response to the earlier message. The response may even come from a separate email or the subject may have even changed.

Another example is when your recipient has  set up elaborate email forwarding between their accounts. Ie, you send an email to someone who has their mail forwarded to another email account (which they then reply from) and the fact that it is a “response” may have been stripped in the forwarding process.

Close Calls
Sometimes a response is received a few minutes before the followup should be sent. Given the volume of email that our partner’s system has to process (, it may take a minute or two for the response detection to trigger. Close calls, therefore, slip through sometimes.

Your Email Provider Might Be Throttling Responses
Sometimes, your email service provider will throttle the number of connections. It may also require re-authorizing an external system. If you suspect a connection problem with your email service provider, head over to your connected services page, disconnect and reconnect your email account (note if your inbox shows as disconnected), or contact support.

Side-Note For Email Nerds
In case you are technically inclined and are wondering how this works, here are more details: In short, looks for a header called ‘in-reply-to’. If this exists, and references the message-id of a followup you scheduled earlier, it tells us to cancel the followup. Here is a bit more detail with an example:

  1. You send an email to someone and, bcc
  2. FollowUpThen receives the email, notes the message-id, schedules a followup and tells to ping us if that email gets a reply.
  3. monitors your inbox for a reply by monitoring “in-reply-to” header of incoming emails. If  that “in-reply-to” field matches the message-id of the followup you scheduled in #1, voila!
  4. ping us. We find the followup and cancel it.

Now you can see where responses might slip through the cracks. For example, a ticket system may not put the original message-id back in the “in-reply-to” field in the reply. Or, someone may copy and paste a reply in a new email with the same subject. If that message-id is lost, we cannot detect it as a response.

Contact Us If Needed
If you’re stumped, contact us! We want to make sure you get the most out your FollowUpThen upgrade.

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