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  • =?UTF-8?Q?Best_practice_using_=e2=80=98unique=e2=80=99_basic_and_en?= =

    From None@21:1/5 to All on Wed Feb 22 20:58:41 2023
    I was thinking of reviewing the basic and enhanced status codes that I
    am generating, because I would like to have more insight into at what
    stage, what code is being generated.

    For instance I am using the 550 5.7.1 for dns blacklists, but also for
    spf hard fail. I am also soft failing messages @gmail.com / @outlook.com
    with this status.
    The accompanying message describes clearly what is going on, but this
    message is sometimes not relayed back to the sender. Even worse is, if
    only the 5.7.1 code is relayed back to the sender (thus without my error message) with some huge manual on how to setup spf. Afaik is 5.7.1 not
    really specific to spf.

    This makes me wonder about these questions:

    Q1. Does anyone know what smtp implementations are doing when they
    receive an ‘uncommon’ error code, are they then more likely to return
    the accompanied error message to the sender? (Or is there a code that
    requires the message to be relayed)

    Q2. Am I allowed to start reject mail on codes like this:

    599 5.0.11 dnsbl spamhaus
    599 5.0.12 dnsbl spamcop

    For the spf I can use 5.7.23. But when I reject a message from
    [email protected] not originating from outlook.com spf servers. I do not
    want to use this code because, I do not want outlook.com to reference
    some manual about the spf hard fail.

    599 5.0.21 spf fail
    599 5.0.22 spf soft fail

    Q3. When should I use a ‘correct’ status like 5.7.25 for reverse lookup failed and inform spammers how to set up their spam environment, or just
    us an ‘uncommon’ status code.

    Q4. What value do these status codes still have. I have the impression
    that sender environments the likes of sendgrid/messagelabs don’t do
    anything with this information.



    [1]
    https://en.wikipedia.org/wiki/List_of_SMTP_server_return_codes https://www.iana.org/assignments/smtp-enhanced-status-codes/smtp-enhanced-status-codes.xhtml

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  • From Claus =?iso-8859-1?Q?A=DFmann?= @21:1/5 to None on Thu Feb 23 08:02:49 2023
    None wrote:
    I was thinking of reviewing the basic and enhanced status codes that I
    am generating, because I would like to have more insight into at what
    stage, what code is being generated.

    Isn't all the information in your logs?

    For instance I am using the 550 5.7.1 for dns blacklists, but also for
    spf hard fail. I am also soft failing messages @gmail.com / @outlook.com
    with this status.

    "soft failing" with 550?

    The accompanying message describes clearly what is going on, but this
    message is sometimes not relayed back to the sender. Even worse is, if
    only the 5.7.1 code is relayed back to the sender (thus without my error message) with some huge manual on how to setup spf. Afaik is 5.7.1 not
    really specific to spf.

    Of course not. It's defined in the RFC.
    X.7.1 Delivery not authorized, message refused

    Q2. Am I allowed to start reject mail on codes like this:

    599 5.0.11 dnsbl spamhaus
    599 5.0.12 dnsbl spamcop

    599? No....

    X.0.0 Other undefined Status
    doesn't make much sense.

    For the spf I can use 5.7.23. But when I reject a message from [email protected] not originating from outlook.com spf servers. I do not
    want to use this code because, I do not want outlook.com to reference
    some manual about the spf hard fail.

    Why not?

    Q3. When should I use a 'correct' status like 5.7.25 for reverse lookup failed and inform spammers how to set up their spam environment, or just

    Do you think spammers care?

    Q4. What value do these status codes still have.

    No idea.

    --
    Note: please read the netiquette before posting. I will almost never
    reply to top-postings which include a full copy of the previous
    article(s) at the end because it's annoying, shows that the poster
    is too lazy to trim his article, and it's wasting the time of all readers.

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  • From None@21:1/5 to All on Thu Feb 23 14:17:55 2023
    None wrote:
    I was thinking of reviewing the basic and enhanced status codes that I
    am generating, because I would like to have more insight into at what
    stage, what code is being generated.

    Isn't all the information in your logs?

    Yes but if someone complains, it is easier to find in the logs what
    actually happened.


    For instance I am using the 550 5.7.1 for dns blacklists, but also for
    spf hard fail. I am also soft failing messages @gmail.com / @outlook.com
    with this status.

    "soft failing" with 550?


    Yes, lots of [email protected] spam is not coming from the gmail/google
    servers. And since google does not use -all. I am rejecting the ~all,
    that seems to work quite well.


    Q2. Am I allowed to start reject mail on codes like this:

    599 5.0.11 dnsbl spamhaus
    599 5.0.12 dnsbl spamcop

    599? No....

    X.0.0 Other undefined Status
    doesn't make much sense.


    So there is no way of using unique status codes, so I know just from the
    code what happened?

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  • From Claus =?iso-8859-1?Q?A=DFmann?= @21:1/5 to None on Thu Feb 23 09:37:30 2023
    None wrote:

    599 5.0.11 dnsbl spamhaus

    599? No....


    X.0.0 Other undefined Status
    doesn't make much sense.

    So there is no way of using unique status codes, so I know just from the
    code what happened?


    You can use "unique status codes", but:
    - make sure your codes make sense, i.e., match the "idea" of the codes.
    so: don't use 599: it's entirely bogus.
    5.7.x would be more appropriate than 5.0.x for your case, right?

    - try to avoid using codes which already exist for another purpose.

    Best approach: try to register your codes with IANA?


    --
    Note: please read the netiquette before posting. I will almost never
    reply to top-postings which include a full copy of the previous
    article(s) at the end because it's annoying, shows that the poster
    is too lazy to trim his article, and it's wasting the time of all readers.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)