Valid RCPT command must precede DATA

xanadu

Active Member
Sep 25, 2006
27
2
153
This is the situation:

myownserver1.com can receive mail on all cpanel accounts and can send emails when using the ISP outgoing mail server or by using webmail. However, if we attempt to use mail.myownserver1.com as the outgoing server address we gat a 503 error.

If we transfer a cpanel account that has had this issue to another of our servers, myownserver2.com, and without changing any email client settings, it all works fine.

I have exhausted my knowledge with WHM and cannot find a problem with thw SMTP server settings......Help anyone?

CORRECTION> Transferring a cPanel Account to another server does NOT make any difference.

Do I have a DNS issue?
 
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cPanelMichael

Administrator
Staff member
Apr 11, 2011
47,908
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However, if we attempt to use mail.myownserver1.com as the outgoing server address we gat a 503 error.
Hello,

Could you let us know the specific error message you receive, and the corresponding output in /var/log/exim_mainlog when this happens?

Thank you.
 

xanadu

Active Member
Sep 25, 2006
27
2
153
Thank you for your response.

The error message is:
Code:
'[email protected]' on 14/02/2017 4:47 PM

503 Valid RCPT command must precede DATA'

From exim_mainlog:
2017-02-14 16:46:57 H=c110-20-92-214.rivrw9.nsw.example.com.au (somename) [110.20.xx.xx]:56531 F=<[email protected]> rejected RCPT <[email protected]>: Rejected relay attempt: '110.20.xx.xx' From: '[email protected]' To: $
2017-02-14 16:47:00 H=c110-20-92-214.rivrw9.nsw.example.com.au (somename) [110.20.xx.xx]:56531 Warning: "Detected session with all messages failed"
2017-02-14 16:47:00 H=c110-20-92-214.rivrw9.nsw.example.com.au (somename) [110.20.xx.xx]:56531 Warning: "Increment slow_fail_block Ratelimit - c110-20-92-214.rivrw9.nsw.domain.com.au (somename) [110.20.xx.xx]:56531 becaus$
2017-02-14 16:47:00 SMTP connection from c110-20-92-214.rivrw9.nsw.example.com.au (somename) [110.20.xx.xx]:56531 closed by QUIT
Hope that all helps you help me!
 
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sktest123

Well-Known Member
Jan 31, 2017
99
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kochin
cPanel Access Level
Root Administrator
503 Valid RCPT command must precede DATA' seems to be authentication issues for mail relaying (remote smtp)
"503 Valid RCPT command must precede DATA essentially means that the server was unable to accept the message, usually because the SMTP connection was not properly authenticated. In cPanel/WHM servers, authentication can happen either through POP-before-SMTP or through SMTP authentication. If the user has not configured Outlook for outgoing mail SMTP authentication, and has not connected to the POP server before sending the mail, this error is returned".
 

cPanelMichael

Administrator
Staff member
Apr 11, 2011
47,908
2,216
463
Hello,

The "Valid RCPT command must precede DATA" error message typically suggests SMTP Authentication is not enabled in the email client. For instance, with Outlook, this typically happens when "My SMTP server requires authentication" isn't enabled.

Thank you.
 
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Sharki

Registered
Nov 4, 2017
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spain
cPanel Access Level
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Hello
I have the same problem (error 503) and infact smpt auth is not checked.
but if check the smtp auth port 587/tls, then outlook 2007 tell me that server don't support kind of crittography used by client.
no problem instead using the same configuration with outlooj 2013
i don't know what i can do
regards
Francesco
 

cPanelMichael

Administrator
Staff member
Apr 11, 2011
47,908
2,216
463
but if check the smtp auth port 587/tls, then outlook 2007 tell me that server don't support kind of crittography used by client.
no problem instead using the same configuration with outlooj 2013
Hello,

That particular issue is discussed on the following thread:

SOLVED - Unable to send emails properly

Thank you.