Hi All, I'm using postfix as an MX server which delivers email to the final recipient using virtual aliases. The version number according to rpm is postfix-2.3.3-2.1.el5_2, that is the version which is supplied in the main CentOS5 yum repositories. This is working perfectly except for one problem. Occasionally postfix will reject an email with the following error:
Feb 12 00:41:24 mail1 postfix/smtpd[24782]: NOQUEUE: reject: RCPT from unknown[111.111.111.111]: 550 5.1.1 <recipi...@example.com>: Recipient address rejected: User unknown in virtual alias table; from=<sen...@example.net> to=< recipi...@example.com > proto=SMTP helo=<example.org> This is a very intermittent and short lived error. Emails to recipi...@example.com were working before the error and start working again a few seconds after it. Based on my debugging it seems that this error is related to me running postmap to rebuild the virtual_alias table This is despite the fact that the recipi...@example.com address is correctly configured in both the old and new virtual_aliases. Here a log of what was happening at the same time as the above error: 2010-02-12 00:40:39,345 - 24597 - DEBUG - Writing virtual_aliases and virtual_domains 2010-02-12 00:41:20,496 - 24597 - DEBUG - Done writing virtual_aliases and virtual_domains. 2010-02-12 00:41:20,506 - 24597 - DEBUG - Running postmap virtual_domains. 2010-02-12 00:41:23,555 - 24597 - DEBUG - Done running postmap virtual_domains. 2010-02-12 00:41:23,556 - 24597 - DEBUG - Running postmap virtual_aliases. 2010-02-12 00:41:24,107 - 24597 - DEBUG - Done running postmap virtual_aliases. Maillog doesn't have millisecond precision so I can't see exactly when the "User unknown in virtual alias table" error was logged but it happens either while "postmap virtual_aliases" is running or very shortly (within a second) afterwards. The same pattern repeats itself in other cases of the same error. The error always seem to happen within a second or so of "postmap virtual_aliases" finishing. So my questions are: 1. Does my analysis seem correct? 2. Is this a known problem? Are there any known race conditions in reloading the virtual aliases config by running "postmap virtual_aliases" 3. Is there anyway I can fix or work around this problem? Would upgrading help? 4. If I switched to using a SQL or LDAP backend for the table lookups would this problem go away? Thanks in advance, - Richard
