Hi! Turns out the "Adding MailCore to Your iOS Project" (http://libmailcore.com/#iosadding) instructions were missing one critical step: Adding libmailcore.a to the list of linked libraries! I've since updated the docs, if you were having linker errors please try the latest steps. Thanks to Goutam Reddy for pointing this out. -- Matt Ronge email@example.com iOS Developer & Consultant Central Atomics Inc.