Reverse-engineering Gmail: Initial remarks

For the last week and a bit, I have been trying to do a particular something with Gmail. (Specifically, get at the Message-ID headers of messages.) This has been mostly a failure, but that’s not so surprising, as I had little experience with “all this web stuff”: JavaScript, AJAX, DOM, browser incompatibilities, Firebug, Greasemonkey… round up the usual buzzwords. I have learnt a bit, though, and thought it might help others starting in a similar situation. (And there’s also the hope that someone might actually find this and help me!)

The story so far
Gmail was launched in April 2004. Since then, it has been through many changes, the latest around October 2007 when there came to our inboxes a “Newer version”, also sometimes called “Gmail 2”. (Note that officially Gmail is still in Beta; it hasn’t even released a 1.0!)
When Gmail was released the set of practices that go by the name of “AJAX” was still new and unfamiliar; it has been refined and better-understood since. (And it turns out to require neither asynchrony nor JavaScript nor XML.)

Johnvey Hwang reverse-engineered much of Gmail’s original version, and even made a “Gmail API” out of it. It no longer works of course, and the site is often down too, but it’s available on the Wayback Machine and the section documenting “the Gmail engine and protocol” is still worth a read, if only for its glimpse into the labyrinthine ways in which Ajax applications can work. He turned it (in May 2005) into a SourceForge project (“Gmail API”), last updated June 2005, and the associated Google Group (” Gmail Agent API”) is also largely defunct and indicates that the API, or whatever came of it, has not been working since the changes in October 2007, at any rate.

My goal
At this point, I might as well reveal what I want to do: I want to make it easy to get the “Message-ID:” header of messages in Gmail. (I like to read email in Gmail but not to send, so one way to reply to a specific message would be to get the Message-ID and ask my other mail client to reply to the message with that message-ID.) In the current interface, the (only) way of getting it is to click on the pulldown menu next to “Reply”, and click on “Show original”. This will open up a page that contains the raw text of the message with all its headers, and “Message-ID:” is always one of them. Since I use Firefox, I’ve been trying to make this easier with a Greasemonkey script.

Trap-patching the P() function
As Greasemonkey scripts for Gmail go, much useful information comes from Mihai Parparita, who wrote many Greasemonkey scripts for Gmail. Quoting from here:

As others have documented, Gmail receives data from the server in form of JavaScript snippets. Looking at the top of any conversation list’s source, we can see that the D() function that receives data in turns calls a function P() in the frame where all the JavaScript resides. Since all data must pass through this global P() function, we can use Greasemonkey to hook into it. This is similar to the trap patching way of extending Classic Mac OS. Specifically, the Greasemonkey script gets a hold of the current P() function and replaces it with a version that first records relevant data in an internal array, and then calls the original function (so that Gmail operations are not affected).

Clever. This same information is also documented at Greasespot wiki, with a few remarks on what different parameters to P() mean. Alas, it no longer works, because Gmail changed their functions around and renamed all of them, so there is no P() function anymore, and I can’t find what the new equivalent is, or if there is one.

Changes of October 2007
Gmail made certain changes in October 2007, including introducing a “newer version”, but also changing the “older version” that is still available: so it’s not really the older version. As far as Greasemonkey scripts go, another change was in January 2008, where they made all the Javascript load in a separate iframe. So “unsafeWindow” in a Greasemonkey script now refers to this iframe (which is the first frame, frame[0], in the window, and can also be got as top.js). So any scripts written in September 2007 or earlier are certainly useless now.

A lesson from all this is that Gmail will always be a moving target, and one must consider whether it’s worth chasing it.

Gmail’s Greasemonkey “API”:
Sometime in November 2007 or so, after the latest changes, Google even released a basic Greasemonkey API for Gmail, which lets you do a few things, like adding things to the pane at the left. It is too limited for what I need, but it works very well for what is meant for, and is also very well-documented, by Mark Pilgrim with his usual “Dive Into” excellence. It is comprehensive, accurate, well-illustrated and to-the-point, and great as documentation goes; it just happens that the API doesn’t provide what I need.

Some observations
Back to what I’m trying to do. Currently, the actions in the menu next to “Reply”, namely “Reply to all”, “Forward”, “Filter messages like this”, … “Show original” etc., do not actually appear in the DOM multiple times once attached to each message. Instead each of these actions corresponds to exactly one node (each) in the DOM, like these:

<div act="27" style="padding-left: 19px;" class="SAQJzb" id=":t6">Filter messages like this</div>
<div id=":t8" class="R10Zdd" act="29" style="padding-left: 19px;">Add to Contacts list</div>
<div id=":tc" class="SAQJzb" act="32" style="padding-left: 19px;">Show original</div>

etc. The IDs change, and the class name also seems to randomly change between “SAQJzb” and “R10Zdd”; the only constant between the action and the node is the “act” attribute. “Show original” is always act=32. So when you click on the down-arrow button next to Reply, this menu comes up, and when you click on something in the menu, it somehow uses the information about where this menu came up and what you clicked, to find out which message to act on.

This means that simply simulating a click on the node (initMouseEvent, etc…) does not work; we also have to somehow give it the information on what message to act on. How to do this is one thing I’m trying to find out.

The other way involves the fact that Gmail also has its own “ID” for each message. When you are looking at a thread (“conversation”) that contains a single message, it is the same as what is in the URL, e.g. if the URL is something like https://mail.google.com/mail/#inbox/11c177beaf88ffe6, Gmail’s ID of the message is 11c177beaf88ffe6. But when you’re looking at a thread containing more than one message, the ID in the URL is just that of any of the messages in the thread (usually the first one, but you can use the ID of a different message in the URL and it will show the same thread). And when you click on the “Show original” link, the URL is something like https://mail.google.com/mail/?ui=2&ik=1234567890&view=om&th=11c177beaf88ffe6 where 1234567890 is a constant (probably depending on the user) and “om” probably stands for “original message”, and the “th” parameter is the ID of the message. So if I can somehow find a way of getting the ID of messages (like the trap-patching P() method, except that it should work for the current version), then it is possible to get the Message-ID headers of messages too.

Neither has worked out yet, but I’m trying…
(And I have more to say, but will post when things actually work.)

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Does RMS have a Gmail account?

Random funny image I remember saving from ages ago:

Google wants me to “Invite Richard to Gmail”.

Gmail has IMAP!

Finally. Many thought this would never happen.

And just like Free software usually, it seems to be the handiwork of someone scratching an itch.

Notes:

• IMAP folders are Gmail labels. Gmail labels show up as folders in your client, and moving a message to a folder in your client simply adds that label in Gmail.
• In particular, be careful creating folders, and avoid making a mess. Try reusing the default Gmail labels: Set your client’s drafts folder to “[Gmail]/Drafts”.
• Messages with multiple labels appear in each of those folders. So there is some duplication at the client end, of course, but this is unavoidable; the price you pay for forcing a tagging philosophy on software that has different beliefs.
• Conversely, if you want to apply multiple labels to a message through your client, you can use the “poor man’s tagging” that has always been possible — copy the message to each of those folders.
• If you delete a message from a “folder” (other than “[Gmail]/Trash” and “[Gmail]/Spam”), Gmail only removes that label. It is still present in “All Mail”. To actually delete, move to “[Gmail]/Trash”. What happens if you delete email from “All mail”?
• Recommended IMAP client settings: Don’t save sent messages on the server; any mail sent through gmail’s smtp is automatically copied to “[Gmail]/Sent Mail” folder.
• In general, actions sync neatly; see the full table.
• IMAP and POP work with messages, so if you move only one message from a thread to a folder, only that one will get that label, but the Gmail web interface will show the entire conversation with that label. Note that this is only a display thing — it’s not that opening Gmail will give all the messages the label, and when you reopen your client suddenly things are different. (I need to actually check this.)
• You still have Gmail’s amazing server-side spam filtering.
• Some things don’t work.
• Some other things are alleged not to work that I don’t even understand
• Everything.

They got everything in order, made all those pages, and turned on IMAP without making any advance announcement…

Using Gmail with mutt, the minimal way (IMAP update)

As Gmail has IMAP access, it is fairly trivial to get it working with mutt. First, if you’re on Ubuntu/Debian, run sudo apt-get install openssl mutt to get mutt if you don’t already have it. Then, just put the following lines into your ~/.muttrc:

set imap_user = "username@gmail.com"
set imap_pass = "password"

set smtp_url = "smtp://username@smtp.gmail.com:587/"
set smtp_pass = "password"
set from = "username@gmail.com"
set realname = "Your Real Name"

set folder = "imaps://imap.gmail.com:993"
set spoolfile = "+INBOX"
set postponed="+[Gmail]/Drafts"

set header_cache=~/.mutt/cache/headers
set message_cachedir=~/.mutt/cache/bodies
set certificate_file=~/.mutt/certificates

set move = no

Make sure your ~/.muttrc isn’t world-readable; it contains your password. (Alternatively, you can leave them out and mutt will prompt you for the password each time.) Also, if you copy-paste from the above, make sure that you have only “normal” quotes, not “smart quotes” which WordPress might have inserted here into this post.

[Other things I have:

set sort = 'threads'
set sort_aux = 'last-date-received'
set imap_check_subscribed

ignore "Authentication-Results:"
ignore "DomainKey-Signature:"
ignore "DKIM-Signature:"
hdr_order Date From To Cc

I did not include above to justify the “minimal” :)]

Things work perfectly as you would expect them.
One thing to note is that the full headers will still contain the hostname of the computer you send messages from. I have not figured a way of hiding this, and perhaps it shouldn’t be possible.

The End

If for some reason you want to use POP, read on. And tell me why you would want to use POP. The rest of the post is an old version, which i had written before Gmail supported IMAP.

Old Stuff
There is a guide here, which is the first Google result on searching for the keywords Gmail, mutt and Ubuntu in any order, but I would advise against it: it does too much unnecessary stuff using too many unnecessary programs (okay if you don’t care), and involves putting your username and password in a world-readable file (not okay).

There is a guide here, but that site seems down, and so I guess it’s likely to be down again (a DynDNS domain; could be someone’s house), so putting a (fuller) guide here:

First, run sudo apt-get install openssl mutt

Next, in /etc/ssmtp/ssmtp.conf, put
mailhub=smtp.gmail.com:465
UseTLS=YES
Everything else seems to be optional.

Next, create a shell script with the contents
#!/bin/sh
/usr/sbin/ssmtp -au "gmail-address" -ap "password" $@ and put it somewhere in your path (~/bin/gmailout, say) and make it executable (chmod u+x ~/bin/gmailout, I mean) and make sure only you can read it! (chmod og-r ~/bin/gmailout).

Now in ~/.muttrc, put
set pop_host="pops://username:password@pop.gmail.com:995"
set pop_last
unset pop_delete #Just makes mutt not ask, GMail uses config option
set sendmail="~/bin/gmailout"
set write_bcc=no #Important; sSMTP makes bcc non-blind otherwise
and you’re set (remember to make this world-unreadable too: chmod og-rw ~/.muttrc)

You can start mutt, and hit “G” (uppercase G) whenever you want to fetch mail. Can also put exec fetch-mail in ~/.muttrc to have it happen whenever you start mutt, but I find that irritating.

Problems with POP: Not that everything is perfect. I can’t have other mail-transport-agents like sendmail or postfix installed alongside ssmtp. I can’t figure out how to get my crontab reports sent to root, but they do go into ~/dead.letter :D
Also, with mutt I had the habit of adding a my_hdr bcc: my-email-address so that the mail I send is threaded along with the mail I receive (yaay, like Gmail), but somehow there seems to be simply no way of getting Gmail to give me, through POP, those messages I send using an external client. It’s a quirk [bug!] in the way Gmail implements POP. This I’ve fixed by setting mutt’s fcc to /var/mail/my-username, my mail folder. (Of course, if I were in the habit of moving mail to my mbox, I could fcc to mbox too.)
Apart from that, it works fine!