451 4.3.0 Error: queue file write error and virtual_alias_maps map lookup problem

5 msg	postfix/ldap - can one special_result_attribute...
2 msg	mailing list goes to bulk / spam folder
9 msg	SMTP Auth on multiple instances
4 msg	Auto-response, but not vacation
4 msg	bypassing reject_rbl_client for certain recipie...
12 msg	rewritten log
11 msg	Per user SPF and Anti Virus checks
9 msg	Instance on policies
2 msg	Removing internal mailers from headers
7 msg	Open Relay issue
1 msg	Messages not picked up from active queue
3 msg	Semantics question about myorigin
22 msg	mime, header_checks question
3 msg	problem using greylist and gmail

451 4.3.0 Error: queue file write error and vir...
\ Lists (30 Mar 2008)
. \ (Wietse Venema) (30 Mar 2008)
. . \ Lists (30 Mar 2008)
. . . \ (Wietse Venema) (30 Mar 2008)
. . . . \ Dennis Duggen (30 Mar 2008)
. . . . \ Dennis Duggen (30 Mar 2008)
. . . . . \ (Wietse Venema) (30 Mar 2008)
. . . . . \ Chris Richards (31 Mar 2008)
. . . . . . \ Dennis Duggen (31 Mar 2008)

5 msg	Network_biopair_interop errors
1 msg	what means error msg in auth.log (failed to map...
5 msg	problem upgrading from 2.4.5 to 2.5.1
5 msg	failover
13 msg	smtp_fallback_relay

Subject:	451 4.3.0 Error: queue file write error and virtual_alias_maps map lookup problem
Group:	Postfix-users
From:	Lists
Date:	30 Mar 2008

Hi postfix-list

First of all i am new to postfix. That said i have a strange problemen.
Somtimes mails aren't going thru and are returning this message:

451 4.3.0 Error: queue file write error

In the log files there is possibly related message

warning: 32AA2EFBC9: virtual_alias_maps map lookup problem for ...

Most emails are received just fine but a few return the above message.
According to the documentation queue file write error is a message for a
possible timeout???
I went to the local Linux User Group to get some help. But after 2 hours
of debugging checking and rechecking the problem was not localized.
We checked permissions,system resources,mysqlconnection and so on. I am
still puzzled. Why is it not working all the time?

=== Versions ===
Postfix 2.4.5
sqlgrey 1.7.4
Mysql 5.0

Sqlgrey seams not to be the problem, since the error also occures when
sqlgrey is deactivated.

Here are the log files and my configuration files (without comments)

http://duggen.net/postfix_prob/master.cf.txt
http://duggen.net/postfix_prob/main.cf.txt

http://duggen.net/postfix_prob/mailproblog2.txt shows when it goes
through just fine.

http://duggen.net/postfix_prob/mailproblog.txt shows the error:

warning: 97C54EFBD5: virtual_alias_maps map lookup problem for
postmaster

We testet the above message ...

=== virtual file test ===
user = postfix
password = password
hosts = 127.0.0.1
dbname=postfix
query = SELECT goto FROM alias WHERE address='%s' AND active = '1'

=== test virtual file ===
# postmap -q mail \
mysql:/etc/postfix/mysql_virtual_alias_maps.cf

Returns: mail as it should.

===

I hope someone can help with a solution. I'm greatful for any help.

Dennis