TIM.DEHRING  I'm pretty sure this project is dead. I tried going to the site linked from here and it says the domain is for sale. Too bad; I was excited when this first came out.  
(Version 0.3)

GLOBETROTTERDK  It has been ages since the last update. Is the project still active? I really had high hopes for this.  
(Version 0.3)

PENGUIRL  Functionality is limited, as is to be expected in a 0.3 release. However, it is CPU efficient which Thunderbird cannot say, and it works with Gmail which to my knowledge no one has gotten Mulberry to do. For those reasons, Correo is my separate e-mail client for my work account. I'm looking forward to the addition of standard features in the future.  
(Version 0.3)

TIM.DEHRING  I'm hoping this program gets more active development. It shows great promise, and I'm all for a Cocoa-based gecko email client.  
(Version 0.3)

SPACECAT85  This doesn't work well with my IMAP FastMail account because it only shows the inbox, whereas most of my mail is automatically filtered into separate subfolders of my Inbox that aren't showing up here.

Still, Correo is only at 0.2, and what is there already looks promising! Keep up the good work.  
(Version 0.2)

PAUL BOWERS  This latest version is MUCH improved. The ability to send attachments, the greatly improved stability of the application, and the overall look and feel, is really nice. I can tell you right now that I like this just as much as most of the other email clients out there for Mac, and am using this little application right now for my emailing needs, There may be some things that it cant do, or do as well as others right now, but give it time. I like it, alot. Thanks!.  
(Version 0.2)

FAKENTRASH  sorry . . . but it doesn't work with IMAP accounts. also after a restart. but it will be a nice mail app for me :-) see you later  
(Version 0.2)

KODAC  Well, considering to try this out. Just wanted to mention that version .2 was just released so anyone reading these comments wouldn't think the project is dead (I just found out about it myself).

Download link seems to work fine for me, BTW...  
(Version 0.2)

AANHORN  I've been a regular Camino user for years, and always wanted the same open source flavor for my mail client, but Thunderbird, like Firefox just doesn't have the native OS X niceties I need.

Correo, at this point, is a great start, not quite ready to replace Mail.app for me yet, but I'll be keeping my eye on it.  
(Version 0.1)

OSXFACTOR  Great idea. I love Camino, and use Thunderbird, but wish there was a solid Cocoa alternative. If Correo can get some momentum, it could be it.

Seems to handle POP/IMAP pretty well (although my IMAP folders weren't visible until I quit/restarted the program). This is a very early release, about all you can do now is setup an account, check/read/send/mail. There are no font preferences, no search ability, no tagging options. Still for a first "proof of concept", it seems to lay a solid foundation. Can't wait to see more!  
(Version 0.1)

NYMPHE  I like the icon and name :)

The interface seems clear and understandable. I couldn't test it right now, but I hope it works with different encodings -like iso-turkish for instance.

Most Mac users are using mail because of the integrity to the system. It is very difficult thing to do this and to add additional features, so that users choose correo instead of Mail.app  
(Version 0.1)