SMTP error

[jaymoh]

my email account doesn't send back auto respond to the sender this my feedback from horde :
SMTP error from remote mail server after MAIL 550 REQUESTED ACTION NOT TAKEN:
DNS FAILURE

Navald
please can you help me to fix it
thank you

www.zamundaafricanacrobats.com

[jaymoh]

Re: SMTP error

thank you!
auto respond is now working, i tried to figure and fix it...
but the form is sending mass without thank you(success page) respond page how does it work without it, please help?

www.zamundaafricanacrobats.com