[Solved] User unknown in virtual mailbox table

[republicus]

I have one mailbox that is giving bazaar errors.

I have created a mailbox and am able to login via roundcube webmail and send/receive email to other domains on my server without problems.

I am also able to verify the same (above) through a email client like thunderbird.

However, no inbound emails are received to that mailbox from an external mail server.

Code:

Unknown response from mail server (status code: 450)
4.1.1 <mailbox@domain.com>: Recipient address rejected: unverified address: host smtp.domain.local[10.10.0.100] said: 450 4.1.1 <mailbox@domain.com>: Recipient address rejected: User unknown in virtual mailbox table (in reply to RCPT TO command)

If I create a different mailbox with the same domain (mailbox2@domain.com) the error does not exist and the messages are delivered as expected.

Ive tried deleting the mailbox through sentora and recreating the mailbox but the problem persists with this mailbox alone.

I'm at a loss here... Any thoughts?

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[UPDATE]
These forums are strange in that a reply by the original poster when there are no other replies appears as an edit to the original post.
Below you will find the resolution.

I just wanted to report that I resolved this issue.

By default Postfix will cache validations for twelve hours. 

I am using Scrollout F11 as my email/spam gateway and the resolution was found there.
You can remove the cache by:

1. Stop Postfix service

Code:

/etc/init.d/postfix stop

2. Remove the cached validation file

Code:

rm -fr /var/lib/postfix/verify_cache.db

3. Start Postfix service

Code:

/etc/init.d/postfix stop

If you are not using a Scrollout server but are getting this error, it may be resolved similarly by removing the cache file above or by removing similar cached validation files. Follow the steps above but replace step two with the appropriate file for your server.

2. Remove the cached validation file

Code:

rm -fr /var/lib/postfix/smtp_tls_session_cache.db

[TGates]

Thanks for updating with the solution! Those darn cache will get you every time