It would be great to be able to set a (SOCKS) proxy setting within the application* for talking to Gmail/IMAP servers as my work firewall blocks talking to Gmail's IMAP servers from within their network, this would mean I can use Airmail at work (that would be great). ^_^

• I can't set a global proxy within the OS X settings as this would mean all of my network traffic going via that proxy and none of my work systems functioning.

If someone sends you an email with say, 10 questions, when you reply using Airmail, you can't say, "See my answers in red below," and then answer each question, because nothing that is shown from the original email is editable! Not sure why this is, but it would make me a hundred million times more productive when using AIrmail.

Currently labels and folders are used in the same way, because Gmail uses them that way. IMAP does support keywords for messages which Thunderbird uses to tag messages with named tags. It would be great if Airmail would support this instead of folders as labels for IMAP accounts. Currently I cannot use the Todo/Memo/Done functions because they would move messages to a different folder, I would like to use this feature while using folders at the same time.

Apps like iA writer and Markdown have a Focus Mode that only highlight the sentence you're currently typing and fade out the rest. That would be an awesome feature for composing emails:
Example: http://images.computerwoche.de/images/computerwoche/bdb/1842754/890.jpg

Show notification badges in dock icon for new or unread mail.

Need to know, how big the filesizes are (like in Thunderbird)

Click an icon or right click > Insert Table -- Display a grid
User drags mouse across the grid to pick no of rows and columns
Table is created. See attached screenshot.
Allow adding, deleting and resizing rows and columns of the table.

Many other mail programs have a selectable feature to disable indenting of quoted messages in replies and forwards. If a mail thread is very long, the indentation can get unwieldy. Even with shorter mail threads, I find these indentations to be generally distracting.

Apple mail is one program that allows the indentation to be disabled by unchecking "increase quote level". Same for Windows Live Mail.

Server site spam filtering is just a start. We also need some local control. I've depended on SpamSieve for years and that would be my first choice but native support like Appe's Mail spam filtering might suffice.

I use Airmail in fullscreen mode on my Mac constantly. And as such its not very easy for me to drag/drop files into it from finder. I would LOVE to be able to just copy/paste E.g. command+c and command+v files straight into a message like I can in Mail.App. This would be a massive improvement for an already great app in my opinion.

I only want e-mail notifications from a few important senders, not all of them. I should be able to specify the e-mail addresses I want to be notified of.

It would be great to be able to have autocomplete properly add all addresses that have been sent to/received from, as Mac Mail does.

When re-sorting the inbox by subject, sender or other criteria, the current behaviour is to take you immediately to the top of the newly sorted list instead of preserving your placement on the message you had currently selected. This isn't ideal as the goal of re-sorting is usually to see the current message in a new context e.g. - show me all other messages that have the same subject line.

It would be nice to see the size of a message and be able to sort messages from largest to smallest.

To delete a message, I have to click in the sidebar of a message or on the message in the Inbox pane. I should be able to click anywhere in a message (other than on a link, of course) to "select" the message for an action, like Delete. The experience is very inconsistent.

QQmail has huge amount of users in china, but air mail 2 can not add qq mail account.

If you have one email thread going and you want to attach a file to it there is no possible way to do that in apple mail for ios. Doesnt exist in many apps like Gmail and Mailbox. Acompli manages this well.

Capability to create some labels ourselves and associate a color too.