We should have a whitelist option for tells

[Avenger]

What's a white list?

It's a list of people that you could explicitly accept /tells (or other communication) from, in addition to other groups like friends, party members, ls members, people you're trading with, people you are in a duty or instance with, etc..

In FFXIV, this is similar to the way you can only send Moogle delivery messages and items to people who are on your friend list.

How much spam do you get from the delivery Moogle? Not much, unless you count the messages from Square Enix itself ("Thank you for playing FFXIV...") but those are usually things like veteran rewards, which you presumably want!

The main down side of applying this to /tell is that people won't be able to send you direct, private messages from anywhere in the world until you add them to one of your contact lists.