[IMGate] Imail question

[Aaron Wookey]

Sorry for an Imail question hope its not too OT.

I have a problem, i try to send email to a user @ a domain and get it 
rejected as undeliverable. So i dig there zone, telnet to there lowest 
value (primary) MX (MX 0) and get this

421 SMTP service not available, closing transmission channel

So i telnet to there secondary (MX 10) and i can connect send mail etc.

My question is why doesnt Imail reconise that mail cant send to MX 0 and 
send it off the the next mx instead, I though that was the point.

Cheers guys

Aaron