Dear list, We have a mail server with postfix and dovecot where we have mail addresses with local unix accounts (authenticated by pam) and without unix accounts (dovecot passwd-file authentication). The problem only affects those non-unix account mail addresses. (There are also completely virtual email addresses with different domains, also managed by dovecot, but still working fine, for simplicity ignored here; sorry the config is really complicated). All non-unix-account addresses are listed in a postfix table, configured in main.cf by: mailbox_transport_maps = hash:/etc/postfix/mailbox_transport_maps looking like this: user1 dovecot user2 dovecot All this was working fine, before yesterdays (rather big) system-upgrade. Now we get the following error in the mail logs: <user@dukun.de>: delivery via local: user lookup error postfix/local in verbose mode complains: postfix/local[27333]: deliver_switch[2]: local user recip user@dukun.de exten deliver user@dukun.de exp_from dukun postfix/local[27333]: deliver_alias[3]: local user recip user@dukun.de exten deliver user@dukun.de exp_from dukun postfix/local[27333]: deliver_alias: hash:/etc/aliases(0,lock|no_regsub|no_proxy|no_unauth|fold_fix|utf8_request): user not found dukun postfix/local[27333]: dict_pcre_lookup: /etc/postfix/aliases_regex: user dukun postfix/local[27333]: deliver_alias: pcre:/etc/postfix/aliases_regex(0,lock|no_regsub|no_proxy|no_unauth|fold_fix|utf8_request): user not found Dez 23 01:56:03 dukun postfix/local[27333]: deliver_dotforward[3]: local user recip user@dukun.de exten deliver user@dukun.de exp_from postfix/local[27333]: warning: error looking up passwd info for user: Invalid argument It seems like postfix/local is ignoring the mailbox_transport_maps option and trying to deliver itself instead of passing to dovecot, thus finding no entry in the system passwd. After full upgrade config files were merged (no changes in mail config) and a reboot was done. The list of upgraded packages is shown at http://termbin.com/k5ql . As downgrading postfix, dovecot and icu (linking) did not resolve this issue, we are very confused. As this is critical infrastructure for some people, any help is warmly appreciated. regards georg