With regard to spaces/other characters, that’s why I was saying that you could use a standard encoding scheme to encode all of your information within some set of taggable characters.

I didn’t think about the problems reverse engineering Apple Mail.

It’s interesting to me that Apple Mail doesn’t provide a way to access keywords on a message. It uses IMAP keywords to do its junk handling. You would think it could come up with a nice transparent way to handle keywords (try server keywords, try server x-tags, try client x-tags) and simply pass you a vector of keywords that you could read. Likewise, you’d think you could pass it back a vector of keywords that you wanted to set. To me (and maybe I’m missing something) that seems like a very logical feature for a scriptable mail application and if Apple Mail doesn’t provide it, they should be nudged to do so.

A couple of things IMAP keywords are that
* Not all IMAP servers implement them (which would lead to ambiguous support)
* keywords are essentially arbitrary named flags such as /project1. This is problematic for MailTags in that it can deal with spaces elegantly, and things such as due date and notes are out of the question. I would be hesistant to deal with only some metadata and not others.
* really there are 2 options. -1- extensive use of x-headers and embedding the metadata in the message — which leaves some concerns vis a vis confidentiality of the actual metadata if the email is replied or forwarded
and -2- pretty much what you described — the use of x-headers to contain a mailtags ID that would refer to a message in a imap mailbox that would contain the actual data — so if the message was forwarded, the only x-header would be an uid to the data not the data itself.

Interms of working on it — it means I have to sit down and wrap my head around Mails implementation of IMAP a lot more — dealing the network i/o — (Mailtags only has to deal with message once it recieves them so network i/o is not an issue) You have to remember that I Mail is not open source so I am pieceing together how it works — it took a good 4 months of solid work to get MailTag up to the state it is, IMAP will not be instant. This is also not my day job… so — thatis the picture — However MT is open source and I do welcome collaboration — if people want to contribute great!

I don’t know. I couldn’t programme my way out of a wet paper bag.

The developer Scott Morrison happens by here from time to time. He ought to know. He’ll be busy with the new MailTags beta, but perhaps he’ll give you an answer.

I know that other applications (PINE, for example, though Thunderbird has weak IMAP keyword support) are able to store whatever IMAP keywords you like. I don’t know if IMAP keywords have a length restriction, but if they didn’t, it seems like you could encode all of the MailTags information as a big (base64-encoded?) IMAP handle.

Even if that’s not possible, if one day you can configure Apple Mail to actually hide some mailboxes, you could store a mailbox with configuration data in it. This mailbox could store a list of all of the information about every message. Then each message just has to store an IMAP tag linking it to that configuration data. On top of that, the configuration data would be hidden from the mailbox list (assuming an “unsubscribe” feature will someday be built into Apple Mail) so everything would be transparent. Is that a viable solution?

Scott