How can I send long messages over long distances?

Question

For communicating short messages (of 25 words or less) over long distances, we have the Sending spell. However, if I wanted to communicate, say, the contents of a 1-page letter (i.e. long enough that simply casting Sending multiple times isn't good enough) to someone far away (on the same plane, probably on the same continent, but many weeks away by land travel), is there a spell or other magic that can accomplish this? A solution might involve physically teleporting the letter itself, or simply conveying the message via some other means. Although sending the letter as a physical object would probably be preferable, unless you're expecting the recipient to be constantly prepared to take dictation at any time.

It can be assumed that the intended recipient is living in a city and not traveling around much, so for example a spell that sent the message to their place of residence rather than directly to them would be fine, as long as the message isn't so ephemeral that it appears and then disappears before they get home from their grocery shopping. It would also be acceptable if some reasonable amount of setup was required to create a "receiving station". I, on the other hand, am a busy adventurer constantly on the move, so an elaborate or non-portable setup on the sending end is probably not viable.

One obvious method of accomplishing this task is to use a 7th level spell slot to teleport to the recipient and deliver the message in person. So that puts a sort of upper limit on what should be required: a better method should be more efficient than teleporting there yourself.

Since this is pretty open-ended, you can impose reasonable additional constraints in your answer, such as requiring the recipient to also be a spellcaster. Just be clear about what your solution requires.

Answer 1

A few 5th level options

One of the best options is the 5th level spell Dream. With this spell, you can converse with a person known to you while they sleep, as long as they are on the same plane of existence as you. If you aren't trying to damage or impair them with this spell, the spell automatically works. And best of all...

The target recalls the dream perfectly upon waking. [PHB, p.236]

If the recipient of the message you intend to send is in a location with a permanent teleportation circle, (such as an academy of magic or a major temple of a powerful religion), then you could also use the 5th level spell Teleportation Circle. It can transport "creatures". You could find a mouse, tie your message to it, and have an ally toss it through the portal that the spell opens (you couldn't toss it yourself, since you already took your action to cast the spell, and the portal only lasts one round).

With some specific subclasses, there may be other options as well. As an example, a Wizard of the School of Illusion could cast Magic Mouth on the wall of the room of a minion, who is given instructions to stand in front of it and say a specific phrase every day at an appointed time. The mouth could be programmed to appear and say "nothing to report" over and over for 10 minutes when the minion says its trigger phrase. Then, when the Wizard wants to contact the minion, they could cast the 5th level spell Scrying on the location, and thus see the mouth activate. The Wizard could use their "Malleable Illusion" ability:

Starting at 6th level, when you cast an illusion spell that has a duration of 1 minute or longer, you can use your action to change the nature of that illusion (using the spell’s normal parameters for the illusion), provided that you can see the illusion. [PHB, p. 118]

With this, the Wizard could change the message every round, and thus send a long message over the 10 minutes that Scrying last. Since Magic Mouth lasts until it is dispelled, this could be done every day (though it would take up a 5th level spell slot to Scry on the location, in order to "see the illusion").

Answer 2

There are a few possibilities that come to mind here, some of which are more feasible than others.

Animal Messenger

Animal messenger lets you send an animal a long distance with a short message. A flying animal can travel about twice as fast as walking, and can go for one day plus two days per extra spell level.

Normally, you can only send 25 words with an animal messenger, but there's nothing saying that you can't tie a longer message to the animal, and then send it off that way. The recipient can get a 25 word message telling them to untie the message, and then a much longer message tied to the bird.

Telepathy

While telepathy is one level higher than teleport, it offers an unlimited and fail-safe method of communication with a known target. It has unlimited range and a 24 hour duration, so it can be used anywhere on the same plane for instantaneous communication.

Teleport

On possibility that is technically less costly than teleporting yourself and teleporting back is teleporting the message directly. Teleport can send "a single object" to the designated location, and if you take an object from your target area, you can send messages this way at will with no chance of failure.

Answer 3

The Crystal Ball of Telepathy

All magical crystal balls allow you to use their powers to scry, but the crystal ball of telepathy additionally enables you to communicate telepathically with someone within 30ft of the scrying sensor that it creates.

As per the scrying spell, a subject who is happy to be magically spied on can voluntarily fail the save, and you can also arbitrarily scry upon a location if you've been there before, so it's a reliable way to communicate with allies on the same plane - and it offers a two-way conversation. It is, however, a legendary magical item, so is probably a very expensive solution to your problem.

Answer 4

A Warlock has two ways to do this (besides Dream).

At 3rd level, with Pact of the Chain and Voice of the Chain Master

• With this combo a Warlock could have their Familiar accompany/travel to the recipient and speak directly to him/her through the Familiar, as long as they are on the same Plane.

At 14th level, if The Great Old One is their Patron

• The Warlock can make the recipient a Thrall or have a Thrall accompany/travel to the recipient. The Thrall is charmed and the Warlock can communicate telepathically with the Thrall, as long as they are on the same Plane.

Answer 5

Project Image (7th-level Wizard/Bard)

The Project Image spell (7th level) can be used, provided the location of your choice is within 500 miles and is somewhere you have been before. Then you can just create an image of yourself, see through its eyes, speak through its mouth, etc. Others in the location would be able to communicate in return.

You can combine that with more limited methods of communication, like Sending, to make sure the target of your message is in the location you are going to project your image to.