"In-Game Mail Delay" article omission

The support article titled “In-Game Mail Delay” (for World of Warcraft) has no mention of mails between Real ID or Battletagged friends.

I thought it might be quite possible that mails with attachments between such friends were instant, similar to between guildmates, so having no mention of Battletags or Real ID at all left me still wondering.

Could you please add a line that mentions whether such mail is instant or not?

NOTE: I am not including single characters on a single other character’s friends list in this, only Battletag and Real ID friends. The original character-to-character friend mail with attachments seems obvious enough that its not instant, imo.

I assume you mean this article https://us.battle.net/support/en/article/98485

It does not mention those things because they have no bearing on the in-game mail system. Those systems exist outside the World of Warcraft game. Keep in mind, WoW and the mail system were created before Real ID existed or before the current Battletag system was created.