Unable to authenticate to SMTP server
I have installed the ISPconfig Virtual Appliance and have it running. I am using it primarily for e-mail. After much fooling around with my DNS records I have managed to receive e-mails using Thunderbird. I can connect to the POP3 server. I can send and receive e-mail using the web interface. I can send e-mails to others at my domain. However, I can't send e-mails to anyone else. When I try I get this error.
The specified server was found, but there was no response from the server.
It seems like this is maybe an authentication problem?