Some alts on my account are unable to receive mail: "Not in your alliance"

[Lorilay 12]

I have two alts on my main account that I use to store various mats on. Currently, I am unable to send mail to them or add them as friends, because it says, "Target must be a part of your alliance." This is the case whether I'm logged into that account or from another account. I can send them whispers (although they are only level 1 and cannot whisper back).

 

They have no special characters in their names, and they are definitely a part of the glorious Alliance. Any ideas what's wrong with them?

[Lorilay 12]

For anyone facing a similar problem, the issue is with Elysium account names from the (filthy) other faction that were flagged for a rename due to Nostalrius characters having the same name.