Outgoing e-mail cannot be sent

If the error occurs in connection with a send connector, please refer to the following article: Outgoing e-mail cannot be sent (send connector)

In this support article, we explain why your outgoing e-mail cannot be sent and is rejected by our mail server.

Error message

553 5.7.1 <info@meine-domain.de>: Sender address rejected: not owned by user mail@meine-domain.de


You do not have the necessary rights to use the sender e-mail address to send e-mails, because the sender address is different from the address of your mailbox or your e-mail aliases.


The sender address you are using does not belong to the mailbox with which you have registered on the SMTP server. Please check the correct spelling of your e-mail address and correct the address in the settings of your e-mail program.

If you want to use a different e-mail address for sending e-mails, the sender address must be added to the mailbox as an e-mail alias. Detailed instructions on how to set up e-mail aliases can be found here.

Which sender addresses can I use?

For outgoing e-mails, the sender address must match the address of the mailbox. The only alternative is to use e-mail aliases. Here you can assign additional e-mail addresses to your mailbox. The e-mail aliases can then be used for sending and receiving e-mails.

Please note that the initial SMTP authentication must always be carried out via the main mailbox. Direct SMTP authentication via e-mail alias is not possible.

  • Mailbox address
  • E-mail alias address

If your mailbox address is info@meine-domain.de, you can initially only use this address as the sender address. To be able to send e-mails from the same mailbox, e.g. from service@meine-domain.de, this address must first be added as an alias. You can find detailed instructions on how to create e-mail aliases here.