> Munging 'From' by mailing list does often include putting the original > From into a *Reply-To* header, which causes replies to go to the > oauthopr instead of the mailing list.
For instance, an original header: ``` From: 123 <[email protected]> ``` Can be rewritten by the list server to: ``` From: 123 <[email protected]> Reply-To: [email protected] ``` This approach does not disrupt the user's ability to reply to the mailing list. Simultaneously, it allows the server to attach a correct DKIM signature, ensuring the email passes authentication checks. > Email often gets modified in technically important but harmless ways in > transit. For example, There is a very common Sendmail config which > re-encodes any mail arriving with non-ASCII to 7-bit-clean > Quoted-Printable. Some MTAs will re-wrap and re-encode messages with > over-long lines. Sendmail can be configured to work with OpenDKIM, which re-signs the email after these modifications. Within a trusted internal network (Intranet), DKIM may not be strictly necessary. However, once the email enters an untrusted external network (Internet), implementing DKIM is essential to mitigate the risk of email spoofing. On 2026/04/20 15:28:10 Bill Cole wrote: > On 2026-04-19 at 21:33:08 UTC-0400 (Mon, 20 Apr 2026 09:33:08 +0800) > 2380189206 <[email protected]> > is rumored to have said: > > > I'm sorry, I made a mistake. DKIM is still verifying > > christopherschultz.net. > > > > But, munging the 'From' address does not affect the reply, because the > > reply uses the `In-Reply-To` header. > > No. In-Reply-To is a header that contains the message ID of the message > being replied to. > > Munging 'From' by mailing list does often include putting the original > From into a *Reply-To* header, which causes replies to go to the > oauthopr instead of the mailing list. > > > By the way, if the DKIM is corrupted, this email should normally be > > rejected, as it might sent from an attacker. > > Hogwash. > > Email often gets modified in technically important but harmless ways in > transit. For example, There is a very common Sendmail config which > re-encodes any mail arriving with non-ASCII to 7-bit-clean > Quoted-Printable. Some MTAs will re-wrap and re-encode messages with > over-long lines. > > -- > Bill Cole > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [email protected] > For additional commands, e-mail: [email protected] > > --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
