failed find host name

[Guest]

I can recieve messages using the outlook (2003) on my laptop which has a
dinamic IP address, but cannot send messages. It used to work fine, couple
of days ago, but suddenly stopped working. when I try to send an e-mail to
somebody I always recieve an e-mail back: undeliverable

Your message did not reach some or all of the intended recipients.

550 relaying to <my em-mail> prohibited by administrator (failed
to find host name from IP address)

How could I sort out this problem?

Many thanks

 

[Brian Tillman]

I can recieve messages using the outlook (2003) on my laptop which
has a dinamic IP address, but cannot send messages. It used to work
fine, couple of days ago, but suddenly stopped working. when I try to
send an e-mail to somebody I always recieve an e-mail back:
undeliverable

Your message did not reach some or all of the intended recipients.

550 relaying to <my em-mail> prohibited by administrator
(failed to find host name from IP address)

This is usually caused by failure to authenticate to the outgoing server.

 

[Guest]

This is usually caused by failure to authenticate to the outgoing server.

Thanks. But can anything be done in this case?

 

[Guest]

Thank you for pointing out to the possible problem! I sorted it out - had to
select the checkbox -This server requires an secure connection (SSL).