Hello @user312​ , Can you provide some screenshots?

Sure !

I have tried to illustrate the situation below

@user312​ , Try to match period is one day instead of Try to match once. 

Ok, thank you for your quick response! I modified it and will monitor results.

I am not to understanding why this may be the root of the problem since the user passed successfully this step and it's on the email itself that it didn't went through. Any hints here ?

@user312​ , I ask about this case to @eric f11​ , and appears, Users who unsubscribed from email notifications get disengaged.

Can you check if users who get disengaged were unsubscribed from email notifications?

BTW - there should be some notification about this @Product Wishlist​ (Intercom product team should add some notification).

Thanks for the follow-up @roy s11​ 

I have checked but actually it appears the users have not unsuscribed...

@user312​ , Oh... Thanks for clarifying.

Once you update the rule setting with "Try to match once" people are still removing from the path?

So far I haven't noticed any removed from the path but will monitor over the coming days

One other reason could be a situation when a user has hard-bounced issues. In that case, they could pass through the 1st email step but then will be automatically disengaged (as the email server will return a deliverability error).