SMTP returns "Host Unreachable"

[Jim Hoflen]

When I try to send an SMTP email with attachments, the conversation goes
fine until the sender (me) responds to the reciever's ack that I am about to
send DATA. As soon as I try to sent the data, I immediatly get a host
unreachable error, and Exchange goes to the next message in the queue.

It used to work, but OF COURSE, no-one changed anything (sigh...).

Be kind, I'm a newbie.

Jim

[Rich Matheisen]

"Jim Hoflen" <james....@offutt.af.mil> wrote:

Since you're already conversing with the other SMTP server it's
probably the other server that's generating the error. It may be its
way of telling you that it can't relay your message.

Do you forward all SMTP messages to a SMTP relay (your ISP, maybe?),
or do you use DNS to locate the correct destination SMTP server and
connect directly to that server?

------------------
Rich Matheisen
MCSE, Exchange MVP

[Jim Hoflen]

I use DNS to find and then connect directly to the other server. One of my
techs called the distant end, and they said that they had no problems there.
However, they did say that they couldn't ping our server. They could ping
the rest of our subnet, though. They didn't elaborate on what the problem
with ping was (I asumed oit was a loookup error). Could that be related? I
thought once the ports were talking, no further reciever-initiated lookups
would be required.
Jim

Rich Matheisen <r.mat...@worldnet.att.net.NOSPAM.COM> wrote in message
news:377239bf...@msnews.microsoft.com...

[Rich Matheisen]

"Jim Hoflen" <james....@offutt.af.mil> wrote:

>I use DNS to find and then connect directly to the other server. One of my
>techs called the distant end, and they said that they had no problems there.
>However, they did say that they couldn't ping our server. They could ping
>the rest of our subnet, though. They didn't elaborate on what the problem
>with ping was (I asumed oit was a loookup error). Could that be related? I
>thought once the ports were talking, no further reciever-initiated lookups
>would be required.

Does the receiving SMTP server react in the same fashion if you telnet
to its port 25 and type in the commands? How about if you use a
POP3/SMTP client like Outlook Express and tell it to use the other
server's SMTP server to send messages. Does it react the same way?

The inability to ping can be darn near anything. A traceroute would
point out the problem a little more clearly.