what does '503 valid RCPT command must precede DATA' mean?

[Naomilala]

I've been using Outlook for a couple of years now and have never had any
problems, but since I've moved my computer onto a wireless connection in my
new house outlook won't send any messages... every time I send a message I
get an instant message from 'system administrator' saying that my email was
undeliverable. For example:

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

Subject: RE: Confirmation of degree
Sent: 18/09/2007 16:15

The following recipient(s) could not be reached:

'(e-mail address removed)' on 18/09/2007 16:15
503 valid RCPT command must precede DATA

When I sign into my email account online I can send messages with no
problems but it's quite annoying! Does anyone know what the matter is?
Please bear in mind that I'm not any kind of computer genius so don't assume
that I know anything! Thank you so much,

Naomilala

 

[K. Orland]

This appears to be a server error.
Do you have more than one email account? Is it just one specific account
this is happening to? Does it happen for all recipients or just certain ones?

 

[K. Orland]

If you're running any antispam software, double-check that's not causing any
problems.
Also make sure you're authenticating properly to the email server. If you
use one ISP and are sending mail via another ISP, that is often not allowed.
For example if you're using Comcast as your ISP but trying to send mail for
a Roadrunner account, you have to supply credentials (username and password)
for the Roadrunner ISP to use their server.

 

[Naomilala]

Thanks for the reply, sorry to be so slow getting back again. In answer to
your questions I do only have one email account running through Outlook and
the problem is affecting all recipients. I'm not running any kind of
antispam software so nothing like that should be causing any problems. I'm
not entirely sure what you mean by authenticating to my server or what ISP
means (I said I was clueless!) but I don't see why anything like that should
suddenly have become a problem just because I've switched to wireless
internet - plus I'm still having no problems receiving messages! Any more
thoughts? Thank you so much.

 

[K. Orland]

ISP = Internet Service Provider. They're the people you pay for your internet
connection. In order to send/receive email, you must submit a password to
their incoming/outgoing mail servers.
For example, if you use Tiscali as your ISP you can't send email from
another provider such as an Oxford school account. You must authenticate to
the Oxford servers to send Oxford mail.
Does that make sense?