Here you can learn more about the possible causes of failure in sending e-mails.
The most common error sending messages occur in the following cases:
- Incorrect recipient address. In this case you will get back letter stating that the mailbox or domain does not exist. (Error 505)
- Exceeded indicators of sending limits. You can find information about limitations on our website.
- Exceeded mail quota limit for e-mail account.The solution can be found here.
- An error in e-mail client settings. The problem is eliminated by error correction. The full settings for e-mail client can be found here.
The most common mistakes in this case:
Error 503: valid rcpt command must precede data - requires to confirm SMTP server authentication. For example, in Outlook you can do this by placing a check in "My server requires authentication" in the settings of the outgoing mail server.
Error 553 unable to verify address - also requires a plug check authenticity the SMTP server authentication. Please note that that in "User Name" graph you must enter your full email address, for example email@example.com.