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Unable to send, 'your envolope sender domain must exist' (#5.7.1), when sending from Outlook and OE

markkindred used Ask the Experts™
I have a client who is unable to send emails from her machine. I have set her email account up in both outlook and outlook express and get the same error:

The message could not be sent becuase one of the recipients was rejected by the server.  The rejected e-mail address was 'xxx@xxx.com'. Subject 'test', Account: 'mail.netcom.uk.net', Server: 'mail.netcom.uk.net', Protocol: SMTP, Server Response: '552 sorry, your envolope sender domain must exist (#5.7.1)', Port: 25, Secure(SSL): No, Server Error 552, Error Number: 0x800CCC79

I have set her account up on our test machine and it works perfectly so i'm assuming that its a problem with her PC. I have tried removing and re-installing Office and error still remains.

Any assistance would be appreciated.

Thanks in advance, Mark.
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Dear markkindred,
Just check the antivirus policy on the client system which is having this problem

Top Expert 2008

Greetings, markkindred !

1. Register an important send/receive library file.  Go to Start > Run and type regsvr32 inetcomm.dll

2. Check if antivirus email check is slowing sending and receiving.  Disable it.

Check if other programs running in the background is interfering. Disable one at a time the Firewall, antispyware, antispam, and all Norton programs.

3. In the account settings, Advanced settings, change the server timeout time from 1 min to 5 min

Best wishes!
I think this is a case of setting the "From" and "Reply To" fields to values that Netcom UK will accept.  If you have registered domain bloggs.co.uk and are using this in your From or Reply To fields, then the message is bein rejected because it is not consistent with the Account you are sending the message from.  Have you tried putting in your Netcom UK address in these two fields as a test?

If the test was done from a different broadband line to that where the problem is, it is also likely to be a problem with the broadband provider insisting that the user use their smtp server to send out emails.  e.g. wanadoo seems to insist you use their SMTP server unless you are using Authenticated SMTP.


Hi All,
Thanks for your suggestions. Im going to call on site early next week to investigate so will keep you posted.

When you get an error message as the one stated below, you may need to check if SMTP Authentication is enabled in your Outlook Express.

"The message could not be sent because one of the recipients was rejected by the server. The rejected e-mail address was 'example@domain.com'. Subject 'Read: Test Subject', Account: 'mail.yourdomain.com', Server: 'mail.yourdomain.com', Protocol: SMTP, Server Response: '503 This mail server requires authentication when attempting to send to a non-local e-mail address. Please check your mail client settings or contact your administrator to verify that the domain or address is defined for this server.', Port: 25, Secure(SSL): No, Server Error: 503, Error Number: 0x800CCC79"?

You may refer to flash tutorial below on how to enable SMTP Authentication on your e-mail account, http://support.exabytes.com/tutorials/exabytes_email/email_OE.htm

For instructions on how to configure your e-mail account with other e-mail programs, please visit, http://support.exabytes.com/tutorials/exabytes_email/

Check this out


Thanks guys.

None of the above helped. It was cured by creating a new user in active directory and setting up the email account under the new username. I was unable to copy the dbx files over so assume that the cause was corruption in the outlook express dbx files.

again thanks for your efforts.

PAQed with points refunded (500)

Community Support Moderator