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I have an application server sending mails with SMTP, and this application generates a FROM line that contains a "friendly address" that seems to be refused by Exchange, of the form:

MAIL FROM: "Francois Barriere"<francois.barriere@mydomain.com>

The server (Exchange, but I don't know the version) returns an error. I can reproduce the problem using telnet. If I change for the following FROM line, the address is accepted:

MAIL FROM: <francois.barriere@mydomain.com>

So it seems the first "friendly address" part between the double quotes is the problem. I haven't found any reference to this address format in the RFC...

Is this format supported by SMTP in general? What is the support status of this in Exchange?

Thanks,

François.

francois
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    If I was a mail server, I'd toss that too. Seriously, a FROM without a local-part @ domain isn't a valid, period. – NickW May 21 '14 at 15:12
  • Ooops, sorry. The last part of the address was not shown because of the HTML entities... I have edited the question to fix it. – francois May 21 '14 at 16:18

1 Answers1

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Both the two examples you give are invalid.

MAIL FROM: "Francois Barriere"<francois.barriere@example.com>

is invalid and I would expect most servers to reject it.

MAIL FROM: <francois.barriere@example.com>

is also invalid, but most servers accept it. I have however been rejecting it for years, since rejecting this invalid format got rid of a lot of spam.

MAIL FROM:<francois.barriere@example.com>

is valid. Notice that no characters are permitted between the : and the < characters.

MAIL FROM:<"francois.barriere"@example.com>

is also valid, but it should not be used. Quoting the relevant RFC:

the sending system SHOULD transmit the form that uses the minimum quoting possible.

kasperd
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