in reply to CC with sendmail?

Did you look at rfc822 4.1, where it shows all lower case for cc: and bcc: ?

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Re^2: CC with sendmail?
by haukex (Bishop) on Mar 23, 2020 at 07:39 UTC
    Did you look at rfc822 4.1, where it shows all lower case for cc: and bcc: ?

    The same RFC also has section 3.4.7. CASE INDEPENDENCE, which says:

    When matching any other syntactic unit, case is to be ignored. For example, the field-names "From", "FROM", "from", and even "FroM" are semantically equal and should all be treated identically.
      Sorry, it's been 15+ years since I last used sendmail directly. :-)

      In skimming the rfc, I thought that

      The only syntactic units which requires preservation of case information are: text, qtext, ..., quoted-pair, ...
      implied that it was case sensitive, because quoted-string quoted-string = <"> *(qtext/quoted-pair) <"> includes quoted-pair, and "cc" was defined with quotes, so I assumed it was quoted-string, and thus required case sensitivity. Plus every instance of `cc:` in the rfc was all lower-case. But if `"From"` is explicitly not in that exception, and `"From"` and `"cc"` are defined with similar syntax, I obviously mis-remembered how to interpret those.

      And, after reading the rest of the replies, it's now readily apparent that the sendmail problem was really not specifying the other recipients where sendmail wants them, and the perl problem was not using a modern mail-sending module that are the root causes of the problem. :-) Thanks for the correction.