TL;DR: Devs, please read below for my SSL concerns. Everyone else, give Inky a try; it's a surprisingly nice and full-featured email client hiding behind a deceptively simple UI.

I'll bite. I'm a sysadmin who gets gobs of email per day. Maybe I'm not part of your target market ("Simple! Just works!"), but I'll offer my thoughts in hopes that they're useful.

I've tried it for a bit. Here's what I like about Inky as a mail client:

- Vi default keyboard shortcuts :)

- The dialog for adding arbitrary IMAP servers is outstanding. Leagues better than Thunderbird. For those who haven't tried it, you type in your email address, then it looks up the servers in the MX records of the email's hostname. You click an "Allow" button next to the server that you actually intended to send your password to, and it starts using that server. Excellent.

- AUTOMATIC UNSUBSCRIBE BUTTON. Dude. Maybe this is common in other mail clients but I just spent like ten minutes unsubscribing myself from useless things. Click, click, click. It's catharsis in a box. This alone made my brief spin with Inky worth my time.

- Nice UI for viewing and editing settings. Surprisingly advanced options for eg. caching, displaying and downloading messages, keyboard shortcuts, and so on hidden in the settings.

- Didn't interfere with my other email clients, as promised.

Security issues that I don't like:

- You didn't even warn me when I added my mail server with a self-signed SSL certificate. Sure, the UI does imply that you're not sending my password to that server before I click the "Allow" button, but there's no way for me to even check the SSL certificate fingerprint before I do that.

- You also didn't let me know whether I'm using an SSL/TLS connection at all.

I expect any decent email client to loudly complain about security issues like these. Inky is a broken email client until it does so.

- Storing my IMAP password on your cloud server is not OK. I know my passwords are encrypted with my Inky password, but that's exactly what I'm sending you whenever I log into my Inky account. Thus, Inky employees can access my email if they watch me authenticate with your servers. I'm not convinced. You've ensured that adding new mail accounts is stupid easy, so why are you "helpfully" keeping a copy of my password for me? At least give me the option of storing passwords in my OS keyring. I'd like to know more about the security of this system and your motivations for doing this.

UI things that I don't like:

- Bug: I add a server, then I click on "Compose message," then I add another server, then click back to my message that I previously started to compose. You don't list the new second server in the "From:" dropdown menu, so I thought I didn't add the new outgoing server properly. I have to scrap that message and start composing a new one before both servers show up in the "From:" dropdown.

- You treat an email thread as a linear list of messages. Email threads have inherent hierarchy and structure. I can't see who's replying to who without expanding the quoted parts.

- You group emails together by subject. I have 1,000 nightly automated server emails per each server accumulated over the past five years. Please don't group them together like that.

- In mailing lists, it's conventional to have "Reply All" as the default action, not just "Reply." I'd love if you detected that.

- Please infer my address book from people in my inbox who sent me things. I don't want to type all that again, and it looks like there's no visible way for me to import contacts. Slurping up contact details when I send messages to people would also help with this.

- In threaded email lists, there's so much whitespace that I can't tell where a message ends and where the next one begins. For example, how many emails are visible on the right side of this screenshot? http://i.imgur.com/92cKQ.png

- There's also way too much whitespace in the message list. I could only see 10 messages in my screenshot, which really hurts when I'm scanning through search results. (EDIT: I accidentally clicked on the date header and it gives you more layout options to condense things down)

- This is currently a free product. How are you making money?

It doesn't work on Linux, so I can't use it day-to-day. That said, I really like what you're doing here, and it's certainly a great start. Until then, I'm headed back to Notmuch ( http://notmuchmail.org/ ) for the time being.