The explanations are different from one error to another. If you do not find an explanation among the options proposed in the following, please contact us.
1. An error occurred while sending mail. The mail server responded: [...] [...] is currently not allowed to relay through this server. Perhaps you have not logged into the pop/imap server in the last 30 minutes or do not have SMTP Authentication turned on in your client.
Explanation: So that e-mails passing through your mail server can only be sent by authorized persons, your server does an authentication when you try to send the e-mail.
Solution: Do a "Receive e-mail" before doing "Send e-mail" or activate the "SMTP Authentication" option in the e-mail client settings.
2. The message could not be sent because one of the recipients was rejected by the server. The rejected e-mail address was 'test@test.com'. Subject 'smtp error example', Account: 'test@test.com', Server: 'edomenii.ro', Protocol: SMTP, Server Response: '550 5.7 .1 ... Relaying denied. IP name lookup failed [192.168.45.110]', Port: 25, Secure(SSL): No, Server Error: 550, Error Number: 0x800CCC79
Explanation: So that e-mails passing through your mail server can only be sent by authorized persons, your server does an authentication when you try to send the e-mail.
Solution: Do a "Receive e-mail" before doing "Send e-mail" or activate the "SMTP Authentication" option in the e-mail client settings.
3. SMTP error from remote mailer after end of data: > host edomenii.ro [209.59.134.187]: 550 Administrative prohibition
Explanation: Any e-mail that is sent contains a header where the following data are specified: who sends (From), who receives (To), optionally to which address to reply (Reply-To), optionally to which address to return (Return-Path), etc. If you receive this error, it means that the e-mail you sent does not correspond to the standard and one or more of these fields contain invalid data.
Solution: Check the settings of the e-mail client for the validity of these fields, especially that the e-mail addresses are not missing and are valid. Example of the mistake: the Reply-To field contains a name, without the e-mail address.
4. Sending' reported error (0x800CCC65) : 'Your outgoing (SMTP) e-mail server has reported an internal error. If you continue to receive this message, contact your server administrator or Internet service provider (ISP). The server responded: 503 valid RCPT command must precede DATA.
Explanation: The SMTP server detects errors in the use of the SMTP protocol.
Solution: For any email client, make sure that the SMTP authentication type used with the server is correct. Usually the "Secure password authentication" option must NOT be activated, but the "SMTP Auhtentication" option must be activated. In Outlook you can use the button "Test account settings" or something similar.