I’m trying to send an email using Aspose Smtp through an Office 365 account with multiple mailboxes. If I use my credentials I can send the email without any issues because my account/user name is by default the same as my mailbox name. The account I want to send messages from has multiple mailboxes so I get the following error when I try to send: “The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.7.57 SMTP; Client was not authenticated to send anonymous mail during MAIL FROM\r\n”}"
Is there a way to specify which mailbox to use when sending a message?
How can this be resolved?
Thank you for contacting Aspose Support.
In such case, you can use the
[Exchange Impersonation ](http://www.aspose.com/docs/display/emailnet/Exchange+Impersonation) feature of the Exchange API that allows you to use another mailbox that has permissions to use it. Please try these at your end and share your feedback with us.