571 remote sending only allowed with authentication

[doglovers]

I recently had to reinstall Outlook on my computer, and now I can only
receive messages or reply to received messages but not send messages. When I
send a message I receive a "System Administrator Undeliverable" message
stating the above reason. I have attempted to turn on SPA and SMTP
authentication, neither of which worked. I have always used this email
account in Outlook before, and have never experienced a problem. Can someone
help?

 

[BillR [MVP]]

This means you require a valid username and password before you can send a
message. Often servers only require it to receive a message. The option is
in account properties in the Outgoing Server tab. For most outgoing servers,
you use the same username and a password as your incoming server. So,
checking that option should work. If not, you will need to contact your
service provider to determine what username and password you need.