I accidentally ate my Missive for Ebele too. Tried completing the heart for Skimmer Trainer Ardra, but didn't get another mailing. Instead decided to visit Ebele with nothing in my inventory and when I interacted with her, the option for "I have something for you" or similar popped up. The quest completed and gave me a new different letter. https://wiki.guildwars2.com/wiki/Ebele