Just a quick note that Mac OS X 10.6.1 again breaks compatibility with the earliert version of the Mail.app plug-in. You may should know that Apple Mail does not support third-party plugins at all so what we did is basically a hack (one reason we did not make a plug-in for Safari but a bookmarklet). The solution is simple: choose Help > Install Add-ons… and re-install the Mail.app plug-in to update it. This installs a newer version of the plug-in which will happily work with 10.6.1.

Fresh tweets
Just reinstall the Mail plugin through the Help > Install Add-ons and it will work again. You may have to do this for every new version of Mail or Mac OS X 10.6.x.
I concur with Annard. Installed just fine with 10.6.1.
Sry, that works not for me. System 10.6.1 32Bit,
Installed beta 7 and now only mobileme mailbox account is accessible under Mail app. I reinstalled DTProBeta7 mail plugin but mailboxes not restored. How can I get my mailboxes back in Mail app?
Damn, (Growl) Apple (hiss) Lock-in (cursing), making (spitting) life (growl) difficult.
But for the rest I like Mac.
Purchased and installed DTPro Office 2.0 pb7 09/26/09 on iMac running Snow 10.6.1. Mail plugin does not work. I have tried various fixes including: 1) creating bundles folder, 2) reinstalling Plug-in, 3) reinstalling DTPro Office, 4) Repairing permissions, 5) rebooting. No success.
@Eli: This is a bug in 32 bit mode. The next beta will fix this.
A quick question: where can I download the mail.app plug-in? My Google-fu has failed and I can’t find it at devon-technologies.com .
Thanks in advance for any help!
@ Jake: The mail plug-in is part of DEVONthink Pro Office and installs via Help > Install Add-Ons.
[...] newsletter.Mac OS X 10.6.1 introduced a problem with new installations of DEVONthink Pro Office (see an earlier blog article here). We have fixed this for the next release but you can also work around it manually right [...]