I just found out about two great features of OS X Lion’s mail client, aptly called Mail: server-side, multi-color message flagging and IMAP access to Yahoo mail.
Mail servers: POP vs. IMAP
As you may know, there are two main ways, or protocols, to access your mail on a server: POP and IMAP. POP (“Post Office Protocol”) is a simple, older mechanism that allows a mail client (Apple Mail, Thunderbird, Outlook, etc.) to ask a mail server whether you have new mail, and download messages to your computer or connected device. You can also tell the server to keep a copy of the messages you download, or delete them. So, the basic premise behind POP (as I see it) is that the mail server is just a way station between the machine sending mail to you, and the mail client on your PC.
POP makes sense in a world in which Internet connectivity is slow and storage space on the server is expensive. In other words, not in today’s hyperconnected, always-online world. The basic premise behind IMAP, on the other hand, is that your mail resides on the server; your mail client can access it at any time, of course delete it if you wish, and perhaps even cache it locally for performance reasons. However, the “official” repository of your mail is on the server.
A huge advantage is the fact that it becomes very easy and safe to access your mail from many different machines—your PC at work, your laptop at home, your smartphone, etc. The mail client on each device gets to read mail on the server, but there is one central repository. With POP, you have to make sure that you instruct your client to “leave mail on the server”: if you don’t, the day will come when you are out of the office, need to read an email your boss sent you the day before, and realize that you already downloaded that email from your work PC and deleted it from the server.
IMAP has all kinds of other advantages, such as folders. The feature I want to focus on today, however, is flagging.
Custom server-side flags
The IMAP mail protocol supports flagging a message as important, and of course Mail supports this. The neat thing is that flagging is a server-side attribute: it is stored on the IMAP server, not on the client. Thus, if you flag a message on one machine (say, your work PC), then later retrieve the same message on another machine (e.g. your laptop, or your smartphone), the flag is there.
However, the IMAP protocol also supports “keywords”—additional status indications whose interpretation and visual rendering is left to the individual mail client, but that are also stored on the server. Older versions of the Mozilla Thunderbird mail client used IMAP keywords to store “labels”, which allowed you to mark a message as “Important”, “To do” or similar; messages decorated with different labels were also displayed different (non-black) color. More recent versions have “tags”, which work similarly but can also be customized by the user.
Well, it turns out that, when you flag a message in Lion Mail, you can choose a flag color other than the default red, and the color is stored on the server. In the Lion Mail client, notice that there is a pull-down menu (a triangle pointing downward) next to the Flag button: that’s where you choose the color of the flag you want. If you access your mail from a different mail client, you don’t see the color, but you do see the flag: that is, things degrade gracefully. Yay!
IMAP Access to Yahoo mail
Well, the title says it all. Yahoo offers free POP access to its mail server, in addition to access via its Web-based interface; if you want IMAP access, you have to sign up for premium service. The only exception is the iPhone and the iPad: Apple must have a special deal with them, and iOS devices do get access to Yahoo’s IMAP server.
My wife has had a Yahoo account for as long as I’ve known her, and she is very attached to it. Despite my repeated attempts to get her to switch to Gmail, she remains faithful to Yahoo. Thus, up until OS X Lion, she accessed Yahoo via their POP server on her laptop, and via the special IMAP server on her iPhone and our family iPad. This is an unholy combination; although we always tried to be careful, between laptop upgrades and mail client updates, I have always been worried about inadvertently unchecking the “leave mail on server” option, thereby making my wife’s email inaccessible from her iPhone and iPad—nowadays her primary mail devices by far.
Furthermore, my wife tends to have a rather large Inbox. Actually, this is not surprising if you are used to POP: a mail client can offer to store messages in a folder on your PC, but the server knows nothing about this. So, if you want to have cross-device access to your mail, and still keep old messages for a while, well, the only way is to leave them on the POP server, so that they show up in your Inbox everywhere. Indeed, iOS does a good job in this scenario: you only get to see 50 or so messages at a time, but if you need access to older messages, you can usually get to them quickly via search.
The problem with this approach is that, if iDevices are your primary mail machines (via IMAP), the rare time you access your mail via POP, your client has to download a lot of messages. For us, this got so out of control that my wife simply stopped using her laptop for email. This was a problem if she needed to print an email: the only practical way for her to do so was to forward the message to me, and I’d print it for her.
Well, no more: as of OS X Lion, Apple Mail has full access to Yahoo’s IMAP server. My wife is ecstatic: not only does Mail look very much like the iPad mail client, she also sees exactly the same messages with no trouble at all, and no time spent downloading old messages!
If you are a Yahoo mail user, this is a big win! A hint: if you have already configured access to Yahoo via POP, the easiest thing to do is to (archive your messages and) delete that account, then use Apple’s configuration wizard to add Yahoo back. Go to System Preferences (notMail’s preferences!), choose “Mail, Contacts and Calendars”, and click on Yahoo. Enjoy!