Checking In
Send this when a user has not logged in for a while. It is a short, plain note from the founder with no pitch, a link to the getting started guide, and an open invitation to reply if something broke. Replace the guide link and signature, set the inactivity window that fits your product, and make sure replies reach a person.
Loops
Define inactive before you send
Store the last login date as a contact property your app updates, and build the audience from contacts past your inactivity window. Send from a real person with a reply-to address someone reads, since the email asks for replies. If there is no response, follow up with the Double Tap template, and see the win-back examples for longer sequences.