503 Valid RCPT command must precede DATA

[Andy]

I know this fault has been asked & answered before but none of the answers seem to work for me.

A couple of months ago my provider upgraded their mail servers & I stopped being able to send mail (receiving was ok). The error was an authentication one with the error message 'None of the authentication methods supported by this client are supported by your server'. I turned off SMTP authentication in 'more settings' and that fixed it.

Now, a couple of months later and I'm getting the error '503 Valid RCPT command must precede DATA' and again I can't send any mail (receiving is still ok). Many of the tips say to turn on SMTP auth but if I do that I still get the authentication error. I have also tried the 'logon to incoming server before sending mail' option which cures the authentication error but brings back the 503 error.

Can't even send mail to myself

Any ideas please?

Thanks

Andy.
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[Andy]

PS. As an update I have also tried going to the advanced tab and changing the SMTP box from 25 to 26 but this just locks up the sending message test with no results as does using 587 in this box as does usinf 465 with SSL as well. Help.

PS these errors are the same on two different computers..
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[Roady [MVP]]

Do you have a virus scanner installed which integrates itself with Outlook?
Uninstall this integration part of your virus scanner and try again; you'd
still be sufficiently protected by your on-access scanner part of the virus
scanner. For more details see;
http://www.msoutlook.info/question/20

 

[Andy]

Thanks, good idea but there are no virus scanners on any of my systems, nor have there been for many years with absolutely no problems.

Have contacted the ISP who says it is the Outlook settings (not sure it is myself)..
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[Roady [MVP]]

I see you started a new thread about his. Let's not continue this one then.