Can not get the warband quest!

I created a level 60 trial character someday,as soon as i log into the game, i got a mail from npc which leads to a quest- “Warbands: Warbanding Together”,Later, i ignored the quest and deleted the trial level 60 character. Till now, i have a level 46 character in my account, but there is no Warband Bank Distance Inhibitor ability in the spellbook ,can not get the warband quest on any of my alts,i visited the inn in Tanaris and could not see the npc “Blue”,How can i get the warband quest again?

Turn on the option to see low level quests in Tanaris. I think it’s a level 20 quest.