Thursday, September 26, 2002 11:10 AM
550 5.7.1 Unable to relay for firstname.lastname@example.org
That is your SMTP server's response, to your attempt at sending outgoing email through it.
So, find an SMTP server that WILL allow you to send outgoing email through it, or talk to the sysadmin of that machine, or see what you are providing in the SMTP envelope, in case you can fix something there to make the server accept your outgoing email.
Like, probably it will either only accept mail with return addresses at the same company domain name, or from registered hosts on the internal network, etc.