I'm curious about whether the product name "Postwoman" violates Postman's trademark and whether Postwoman will be getting a C&D letter soon, demanding that the name be changed.
Normally companies don't get to claim broad trademark protection for prefixes -- Facebook has been shut down when trying to broadly enforce its trademark against anything prefixed with "Face" -- but "Postwoman" is close enough and is marketed as a competing product in the same place.
Update: It seems the author is also worried about this. On her blog post announcing the service, someone raised the concern, and she acknowledged that it's a problem: https://dev.to/liyasthomas/comment/ee8m
Normally companies don't get to claim broad trademark protection for prefixes -- Facebook has been shut down when trying to broadly enforce its trademark against anything prefixed with "Face" -- but "Postwoman" is close enough and is marketed as a competing product in the same place.
Update: It seems the author is also worried about this. On her blog post announcing the service, someone raised the concern, and she acknowledged that it's a problem: https://dev.to/liyasthomas/comment/ee8m