Mailing List Message #97806
From: Bill Cole <>
Subject: Re: will leave the Internet...
Date: Thu, 16 Apr 2009 18:28:33 -0400
To: CommuniGate Pro Discussions <>
Mario Jorge Passos wrote, On 4/16/09 3:45 PM:
Thank you very much!!! It is obvious! "Will leave the Internet!" means
it will become local. It is not an error message. I was wrongly
understanding it as an error because, as follows:

We have am outsourced Linux-based PBX that should send alert messages
via our SMTP. The PBX issued a fatal error message when it received the
"will leave the Internet" prompt, as follows.

email: FATAL: Smtp error: 250
<> will leave the Internet
So, it is no longer our problem. It's their problem. :-)

It is absolutely their problem.

The only thing that any SMTP sender should try to interpret in the server response to a RCPT command is whether it starts with a 3-digit number and what the first digit is. Normally success will use '250' but '251' also has a defined standard meaning and the logical model of SMTP response codes includes space for extension with other 2xx codes that describe other types of success. Similarly, 4xx responses are for failures that are likely to be transient (i.e. the sender should retry later) and 5xx responses are for failures that should not result in automatic retry.

If you share that information with them, you might also want to point them at the current and past RFC's defining SMTP, which they apparently are not familiar with:
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