Duplicate entry '' for key 2
Starting in revision [731] of the trunk we added digests emails to Maia. This involves a unique, random token used for each mail/recipient entry in maia_mail_recipients.
If the error includes an empty token, like this: '', then you probably updated the database, but not amavisd-maia, hence it is trying to insert a null and duplicate token into that table.
If you actually do have a token in that string listed, check that you have updated to at least revision [777]. In this revision, it will check for a duplicate key error and try one more time with a new key. If you get a ton of errors like this, and they seem to repeat, then we might have a bad psuedorandom implementation and I would like to know about it... please e-mail the maia-users mailing list.
We might be replacing this token with a structure that is both random and unique from the start, which will solve this latter issue.
