this is a great idea, its unique and will be very helpful
i agree with you about being able to toggle it being on or off aswell as friends or all. obviously if it is all there will be a good chance of spam so maybe a limit per player to a person
ie. a player can send a limit of 3mail to each player and 12messages at max to players who are not listed as friends, but if you have it to friends only i think it should be allowed to be about 5mail to each friend as they are friends and may have more to ask or say.
i agree with you about being able to toggle it being on or off aswell as friends or all. obviously if it is all there will be a good chance of spam so maybe a limit per player to a person
ie. a player can send a limit of 3mail to each player and 12messages at max to players who are not listed as friends, but if you have it to friends only i think it should be allowed to be about 5mail to each friend as they are friends and may have more to ask or say.

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