If you are looking for can’t send mail to that realm wow, please checkout the links below :
1. Mail – Wowpedia – Your wiki guide to the World of Warcraft
https://wow.gamepedia.com/Mail#:~:text=To%20send%20cross%2Drealm%20mail,not%20other%20items%20or%20gold.
2. Cannot Mail Gold or Items to Another Realm or Faction …
https://us.battle.net/support/en/article/10818
3. Can’t send mail to that realm? : wow – Reddit
4. Can you send mail between realms? – General Discussion …
https://us.forums.blizzard.com/en/wow/t/can-you-send-mail-between-realms/132812
5. I cant mail my other character – WoW Help – Wowhead Forums
https://www.wowhead.com/forums&topic=261917
6. Cross-realm mail | WoWWiki | Fandom
https://wowwiki.fandom.com/wiki/Cross-realm_mail
7. Can i transfer items from one realm to another? – Dalaran-WoW
https://www.dalaran-wow.com/forums/input-and-assistance/community-support/topic/11713/can-i-transfer-items-from-one-realm-to-another?login
8. Can you send gold cross realm and faction? – AskingLot.com
https://askinglot.com/can-you-send-gold-cross-realm-and-faction
9. Transfer Your WoW Gold With These Methods | Bit Rebels
https://bitrebels.com/entertainment/transfer-wow-gold-methods/
10. Cross-realm account-bound mail now live, mailing rules …
https://www.engadget.com/2013-12-10-cross-realm-account-bound-mail-now-live-mailing-rules.html
11. I can’t send mail by mailbox. – Forum’s Archive – Firestorm
https://forum.firestorm-servers.com/us/index.php?/topic/20588-i-cant-send-mail-by-mailbox/
12. Connected Realm function(s) – WoWInterface
https://www.wowinterface.com/forums/showthread.php?t=57029