> On Sep 4, 2019, at 9:16 AM, @lbutlr <[email protected]> wrote:
>
> On 3 Sep 2019, at 07:33, Viktor Dukhovni <[email protected]> wrote:
>> You can use "check_sender_access" in combination with a PCRE table:
>>
>> /[^[:ascii:]]/ REJECT 5.1.7 Malformed sender address
>
> That error message is wrong though.
If the MTA does not advertise SMTPUTF8, envelope addresses are
required to be ASCII. A non-ASCII address is therefore malformed,
but the OP is of course free to craft any text message of his
choice.
The important part is the "5.7.1" enhanced DSN status code, but perhaps
better than:
REJECT 5.7.1 ...
would be (<https://tools.ietf.org/html/rfc5321#section-4.2.2>):
501 5.7.1 Invalid (non-ASCII) sender address
--
Viktor.
