Problem with failure notice but the mailbox exist

[Rafael Angarita]

    Hi!

    I'm getting some emails returned  with the message "Sorry, no
mailbox here by that name. (#5.1.1)",  however the mailbox exists.
    It looks like there is not pattern or relations with the addresses
that fails and they not always fails (it's an ocasional failure).

    My environment:
    - Solaris2.7
    - Qmail1.03 patched with qmail-ldap (20010501)
    - Openldap 1.2.11

    Any suggestions about this problem?

    Thanks in advance

--

Rafael Angarita