SMTP error?

[BGSWebDesign]

Ok,

After the move to cpanel, here's the error I see sending a test email to 2 email addresses on my test list:
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Warning: 100% of messages were skipped due to timeout, authentication or unknown error!
You may want to check your settings, enable the SMTP log and send some test messages to make sure they are delivered.


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So, I enabled SMTP log and here's what I see (email addresses changed to protect privacy):
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> EHLO localhost
250-secureXX.apollohosting.com
250-PIPELINING
250-8BITMIME
250-SIZE 0
250 AUTH LOGIN PLAIN
LM: SMTP Pipelining Detected
> NOOP
250 ok
> MAIL FROM: <lmbounce@mydomain.com>
> RCPT TO: <brett@myotherdomain.com>
250 ok
550 sorry, unauthenticated user with dynamic or unresolveable HELO/EHLO (#5.7.1)
LM: Undeliverable. RCPT response: 550 sorry, unauthenticated user with dynamic or unresolveable HELO/EHLO (#5.7.1)
. Skipping.
> RSET
250 flushed
> MAIL FROM: <lmbounce@mydomain.com>
> RCPT TO: <mysecondtest@yahoo.com>
250 ok
550 sorry, unauthenticated user with dynamic or unresolveable HELO/EHLO (#5.7.1)
LM: Undeliverable. RCPT response: 550 sorry, unauthenticated user with dynamic or unresolveable HELO/EHLO (#5.7.1)
. Skipping.
> RSET
250 flushed

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Any idea what's up here DW???  I need to get LMP back up and running, this doesn't sound promising, let me know what you think?

[DW]

After the move to cpanel,

Your previous threads said you moved to Plesk.  I'm a bit confused.  There's cPanel, and there's Plesk - is this a different installation?

Any idea what's up here DW?

250 AUTH LOGIN PLAIN

It looks like this server may require authorization - is AUTH enabled?

> EHLO localhost
..then..
550 sorry, unauthenticated user with dynamic or unresolveable HELO/EHLO (#5.7.1)

Please first look into the AUTH feature, and if this persists I would say you may need to make sure that all email addresses used in ListMail (bounce to email, send from email) exist in your control panel as an alias or a mailbox.  (This is a rare but common restriction)

Regards