Outlook - SMTP Error 451 on just one machine

[Lex]

Hey guys

After a feq months of using a new mail provider, one of our machines
started receiving this message when sending email:

Your message did not reach some or all of the intended recipients.

Subject: xxxxx
Sent: 09/04/2006 11:26

The following recipient(s) could not be reached:

'[email protected]' on 09/04/2006 11:26
451 Temporary local problem - please try later

Things got worse a few days ago when all the messages were bounced
back. I really don't know what to do. The settings are the same on all
the computers. Also the ISP is the same,

SMTP authentication is enabled, SSL is not required. The smtp server is
located on a webserver that we use for our website.

General server information:

Operating system Linux
Service Status Click to View
Kernel version 2.4.21-40.ELsmp
Machine Type i686
Apache version 1.3.34 (Unix)
PERL version 5.8.7
Path to PERL /usr/bin/perl
Path to sendmail /usr/sbin/sendmail
Installed Perl Modules Click to View
PHP version 5.0.5
MySQL version 4.1.18-standard-log
cPanel Build 10.8.1-STABLE 114
Theme cPanel X v2.5.0
Documentation Click to View

Does anyone know what could be causing this problem? Please help.

thanks
Lex

 

[Lex]

Ok Guys

After reading about half the internet i came to a conclusion about this
problem...

I realised that the problem was happening only on a computer using a
separate internet connection. This was due to the fact that it was
checking several accounts at the same time so the mail server would
lock out the actual IP address. Once the connection was reset, the
e-mails started going out correcly.

Therefore, reset your internet connection (or router) and the problem
should be solved. Also try to avoid having too many accounts on
automatic send and receive.

I hope this helps

Lex