Could be door bell. I have video doorbells I set up. Home builder ran cat5e to the old doorbells that terminated in the attic at the doorbell chime block. I snipped and terminated these with rj45s and mounted a small outdoor rates PoE switch in the attic to power the new video doorbells.

I have no idea which route these cables take to get where they go as they disappear under the decking in the attic. Terminating each end worked so I figured all is well.

You’re trying to deliver email to external users.

You really need your email to get through without ending up in people’s spam folder.

So literally everyone actually using email.