Kevin,
Yahoo and the other big services have multiple SMTP servers and all it takes
is one of them to be misconfigured and this can happen. It won't happen all
the time because statistically your server would connect to the lower
numbered MX records first, but if they are all the same value, the chances
are 1 in X (x = number of servers that service has) that your server will
connect to the misconfigured host.
The 'unknown user' message actually comes from the receiving server, when
the 'RCPT TO: [EMAIL PROTECTED]' is sent by IMail, during the delivery attempt.
So all IMail is doing is relaying that error message back to the sender, via
the postmaster message. Since it was the receiver that said 'unknown user',
it is highly unlikely the problem is the sending server (IMail).
Why would another server have 'better luck'? Well, maybe it just did not
connect to a receiver that has the problem. Or maybe someone configured the
sending system so it only talks to a single SMTP receiver, rather than all
of them (an entry in the HOSTS file could do that). Or maybe is was just
chance.
Just because the 'email address is valid' does not mean that all the servers
that are supposed to accept that address really can. They should be, but
with multiple servers, the possibility of one being configured differently
(or having a problem!) grows.
If you believe the address is correct and get an 'unknown user', just send
it again. If it get through, great. Now you will have IMail logs for both a
good and bad delivery attempt and they can be compared. Bet you find that
one of the receiving servers is the one that returns the error message and
others are OK.
Daniel Donnelly
________________________________________________________
----- Original Message -----
From: "Kevin Forte" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Monday, April 02, 2001 1:22 PM
Subject: [IMail Forum] Unknown user - YAHOO
> Do other people using Imail get emails back from Yahoo saying
user-unknown,
> even when the user id is valid? I have been using Imail for about 3
months
> now and I cannot pinpoint when this exactly occurs, but it will happen
from
> time to time. When using Q-Mail, we never get this message back from
Yahoo.
>
> PS The user-ID is valid and does not happen all the time.
>
> Kevin
>
>
> Please visit http://www.ipswitch.com/support/mailing-lists.html
> to be removed from this list.
>
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>
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