Scott Morrison has released a new public beta of his IMAP-savvy MailTags 2.0 plugin.

Public Beta 10 introduces the ability to turn off the automatic saving of tags to IMAP servers and to manage it manually. It also fixes numerous bugs, especially issues related to smart mailboxes and “to do”-related criteria.

Since tagging IMAP messages can create extra bandwidth usage, there is now an option in MailTags’ Preferences to switch off the autmoatic saving of tags to the IMAP server. This preference is on by default. Turning it off means that tags are only saved to the local cache files. You save bandwidth, but the tags are naturally not available to other computers.

For added fine-tuning, you can choose not to save tags on messages over a certain size:

When a message has tags that are only saved to the local cache, an extra button “Save To IMAP” appears at the bottom of the tags panel.

Clicking this button will immediately save the locally cached data to the IMAP server. A similar option appears in the MailTags menu and in Mail’s Contextual menu. Or you can just highlight the message and press ⌃⌘S.

Given Scott’s trademark attention to detail and completeness, a new criterion has been added for smart mailbox configuration: “IMAP Tags are/are not saved to server”.

A new icon in the MailTags column quickly indicates which messages have tags saved to the IMAP server or not. The messages with the orange tag icon have tags saved locally only:

Lastly, as extra insurance, tags not saved to the IMAP server are retained during mailbox rebuilds.

The latest public beta also contains a bucketful of bugfixes. The interface has been firmed up, HUD windows are better positioned, and customised MailTags columns behave better in the Mail Viewer.

Smart Mailboxes based on To Do items, especially on completed items, are smarter and will now work as expected, although you may need to reindex your tags using the new “Reindex Tags” option in the Preferences).

To dos now display using the user’s internationalization (or internationalisation) settings. Huzzah!

MailTags and iCal now mutually update deleted to dos and events more consistently.

Rules management has also been further improved. Two potential crashes when applying or editing rules have bene corrected, and rules are more efficiently applied.

Users with Dovecot IMAP servers will be glad to hear that MailTags no longer overwrites its X-Keywords headers when rebuilding mailboxes.

MailTags’ SpotLight importer has been updated to take account of new to do counts, completion status and IMAP save status.

This long list only picks the best bits out of a much longer changelog on the MailTags web site.

You can read more about MailTags 2.0 and download the new public beta from Scott’s web site , where you will also find a forum for any questions.

The latest public beta of MailTags 2.0 has been released.

It’s unlikely but possible that some Apple Mail users don’t know what MailTags is. It’s a plugin for Mail.app that brings powerful tagging and management to your email, smarter integration with iCal and forms the cornerstone of Getting Things Done with Apple Mail.

Improvements over the previous public beta are most visible in speed, stability and a tweaked interface.

Tagging and opening large mailboxes are both now markedly quicker. Scott has optimized that way rules are applied, postponing IMAP updates to end of rule application.

Stability is also improved. Messages are no longer sometimes deleted when tags are rapidly applied to a large number of messages and the number of temporary duplicates has been reduced. In addition, MailTags now more reliably deletes iCal events attached to the message when clearing all tags via the MailTags pane or menu.

Tabbing through the to-do and event pop-up windows no longer crashes Mail on occasions.

In the kind of nice touch that belongs to an app nearing its final polish, the MailTags tag icon no longer appears printed messages.

In the main MailTags pane, the same polish is noticeable.

The widgets and buttons have been redrawn to match better the overall look and feel of Mac OS X. An Action button on each to-do or events gives quick access to editing/viewing/deleting options.

The pop-up windows have also been reworked a little. Copy and Paste functions now work in the text fields, which also accept non-English characters.

The pp-up windows look good and are easy to work with:

Some niggling problems remain. MailTags and PGP signatures don’t agree with each other. And some beta-testers find that MailTags will sometimes make .Mac accounts reject the account’s password (although a restart fixes that) and sporadic crashes sometimes occur when printing.

Overall, MailTags 2.0 now looks and feels like a plugin that is almost ready to be released in final form.

The prince of Mail.app plugins hovers on the verge of even greater greatness.

You can read more about MailTags 2.0 and download the new public beta from Scott’s web site , where you will also find a forum for any questions.