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:

  1. Incorrect recipient address. In this case you will get back letter stating that the mailbox or domain does not exist. (Error 505)
  2. Exceeded indicators of sending limits. You can find information about limitations on our website.
  3. Exceeded mail quota limit for e-mail account.The solution can be found here.
  4. 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 protected].


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