Mail Delivery System - Undelivered Mail Returned to Sender

Hello!

I have a new error with mail connect.

I upgreded the I-MSCP to i-MSCP 1.1.10 released.

I tested the mail.

If I send a mail to server. The mail arrives successfully, but the server back send a error mail.

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Mail Delivery System - Undelivered Mail Returned to Sender

This is the mail system at host fqhn.server.info.I'm sorry to have to inform you that your message could notbe delivered to one or more recipients. It's attached below.For further assistance, please send mail to postmaster.If you do so, please include this problem report. You candelete your own text from the attached returned message.The mail system<[email protected]>: user unknown. Command output: Invalid userspecified.
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I paste the mail.log and sender headline (source code)

http://pastebin.com/download.php?i=11i8DjCW

http://pastebin.com/download.php?i=E94cuAVA

The server is Debian 6.

What is the problem? Why drop the server the "Mail Delivery System - Undelivered Mail Returned to Sender" error message?

Maybe SpamAssassin do it?

Thx

KALMI

No, I get the mail, because I don't understand what is the problem....
I checked the other live mail and same the error unfortunately.

I paste the received mail source

http://pastebin.com/download.php?i=tTmNwvfy

If I downgrade the last stable version.

BuildDate = 20140525

The server is working perfect. I don't get error message.

I think the new update is wrong.

I would like to ask do I experience this problem?

I have upgraded 1.1.11 version and error didn't come again.

System is working perfect