Ignoring my previous message just for a second, I realized that my config wasn't correct. First the layout: ~mail/ ~mail/Drafts ~mail/Ashley-Feb09 ~mail/Others-Feb09 ~mail-Archives/ ~mail-Archives/2009/ ~mail-Archives/2009/Ashley/ ~mail-Archives/2009/Ashley/Ashley-Dec09 ~mail-Archives/2009/Ashley/Ashley-Nov09 ~mail-Archives/2009/Ashley/Ashley-Oct09 So I (now) have this for namespaces: namespace private { separator = / prefix = "mail/" location = mbox:~/mail:INBOX=/var/mail/%u inbox = yes hidden = no list = yes # for v1.1+ } namespace private { separator = / prefix = "mail-Archives/" location = maildir:~/mail-Archives:LAYOUT=fs inbox = no hidden = no list = yes subscriptions = yes } But when I'm in Thunderbird and I try to subscribe to anything that falls inside of ~/mail-Archives/ it won't work. I can browser all the way down to the folder, but I can't see anything within that folder. For example, consider the full path to the following 'Ashley-Dec09' mailbox: ~mail-Archives/2009/Ashley/Ashley-Dec09 In Thunderbird, when I hit 'Subscribe' I can browse down to '2009' and I can see 'Ashley', but I can't drill down into it and subscribe to 'Ashley-Jan09'. What am I missing here?