I'm trying to setup IMAP settings for an iCloud account using a custom domain. I'm running into a authentication problem. I don't get a lot of feedback from the error: Login to account "sss@yyy.com" failed Login to server imap.mail.me.com with username sss@yyy.com failed I'm using an app specific password [0] and my iCloud account as the username which is also based on my custom specific domain yyy.com. I've also tried my iCloud alias which maps to aliasname@icloud.com as the username as well as "aliasname" without the @icloud.com. No luck with any of the permutations. Any hints on troubleshooting this? Any issues people are seeing with iCloud IMAP and/or using custom domains with it that might help me with this? [0] - https://support.apple.com/en-ca/HT204397