Outlook 2003 - can't send email

  onthelimit1 15:08 14 May 2012

W7 PC with MSE - been using Outlook for years with no problem. Suddenly last Thursday, within seconds of clicking 'send', get a could not be delivered message with code ' 503 valid RCPT command must precede DATA'.

Google only says that this is caused by the server needing authentication. ISP (who's spent ages trying to sort this) says their servers do not. He's sent a message from his PC using my log-in details with no problem. He's checked the settings on my PC and says they're fine. I've tried a System restore to before the problem started (in case it was an update that triggered this), and reset the router to factory settings. I've tried setting up Outlook express and Thunderbird on the spare PC with no success (same message). Ttearing my hair out - anyone any thoughts, please?

  Woolwell 16:43 14 May 2012

Looking through Google search results indicate that the main reason is authentication required. He can send with your details but is this with the same ISP, same smtp settings? Has he had a look on webmail and is the account full? What outgoing port is being used - 25 or 26? Have you tried with authentication and ssl enabled?

  onthelimit1 17:24 14 May 2012

Thanks Woolwell. Yup, same ISP, same settings. Port 25 (have tried 26) He is insistent that his servers will NOT work with 'auth reqd'. What I find strange is that I've done nothing to cause this problem. He didn't mention checking for a full account, but we don't send many emails (just the usual domestic stuff).

  Woolwell 17:39 14 May 2012

I had a whole load of bother with something similar (not the same error message) this morning but this was with a new account and it involved authentication. Unfortunately the Outlook error messages are fairly useless.

Try with authentication. Long shot - try sending with Firewall off and/or email scanning off.

  onthelimit1 17:48 14 May 2012

With auth - no go. Nor with firewall or antivirus off. Baffled!

  Woolwell 18:05 14 May 2012

I wonder if this is a corrupt Outlook profile. Try scanost OST integrity and you can also try scanpst.

It may be worthwhile creating a new Outlook profile and seeing if the account works under that. Create a new profile

  onthelimit1 20:02 14 May 2012

Sorry - forgot to mention I'd done a scanpst on Sat. I'll try another profile but, as I mentioned, accounts in Thunderbird and OE didn't work on the spare PC either. I'm becoming more convinced it's a server problem, but how to convince the ISP?

  Woolwell 20:37 14 May 2012

Sorry. I overlooked that it didn't work in Thunderbird or OE. If that is the case then I think that it may well be a server problem. Assume that you can send from webmail.

  onthelimit1 22:10 14 May 2012

Yes, OK from webmail. I've emailed support again - will wait to see if they react!

  onthelimit1 22:37 17 May 2012

Finally sorted. Seems my IP address had been blacklisted by server software after I'd received a scam email. Must be rare as the ISP technician hadn't experienced the problem before - asked me to rerun anti malware progs and he then set up a new address. That's another solution to go in my little book!

  Woolwell 12:35 18 May 2012

That doesn't make a great deal of sense because I would have thought that your IP address would have changed ever time you switched off the router or did a factory reset. IP addresses are blocked for sending e-mails not receiving them so they seem to say that your system sent spam or other rogue emails.

This thread is now locked and can not be replied to.

Elsewhere on IDG sites

iMac Pro review

Illustrator Charles Williams on how to create magazines and book covers

iMac Pro review

Les meilleures prises CPL (2018)