I need some help with long distance communication in my campaign. Its a low magic campaign, with items being valued at approximately 5* base cost, so I obviously started up a mail order magic item system to abuse this, with craft wondrous items and craft magical arms and armor.
The party currently has access to 2nd level Adept casting, 2nd level Wizard Casting, and 2nd level Cleric casting, with possible use of home brewed unearthed arcana ritual magic to increase it slightly.
Currently for communication I am using human messengers on horses, but that is hideously slow and ineffective. I thought of using Divination spells (Scry or Clairvoyence) to look at notes layed out on a desk, but that's not for another level or two. Whispering Wind is okay, but has a limited range (5 miles at the moment).
Ideally, something that would allow for communcation over 100 miles or so and requires 3rd or 4th level spells that we could make a ritual to put into an item. Does such an item exist? Does anyone have any better ideas?