Change Details

== Current context == When someone (with a recent mailserver, I mean a DKIM-enabled mailserver) sends an email to the WMIT Mailman, it may be cases where the original DKIM firm is valid, but Mailman delivers invalid `DKIM-Signature` signature, and so the email is marked as spam and, often, discarded by receivers. This happens because Mailman alters the original message. This happens in various ways: changing the subject, adding the prefix `[Something]`, altering the body, altering the `From:`, etc. == Problem == Mailman alters the original message and it breaks the original DKIM signature. == Ideal solution == 1. preserve the old DKIM signature in another (non?)standard header (uhm... ?... `X-original-DKIM-Signature:`) 2. delete the sender's DKIM-Signature: since it cannot be valid anymore if Mailman changes the original message 3. just in case, introduce a new DKIM-Signature: header respecting the new message delivered from the mailing list Having said that, I don't think this solution can be implemented easily in Mailman. == Proposed solution == Edit the Mailman configuration file and set `remove_dkim_headers: yes` in order to strip the header `DKIM-Signature:` that usually contains an invalid firm, since the original message was altered by Mailman and so its crypto signature is invalid. Related documentation explaining default value: ``` # Some list posts and mail to the -owner address may contain DomainKey or # DomainKeys Identified Mail (DKIM) signature headers <http://www.dkim.org/>. # Various list transformations to the message such as adding a list header or # footer or scrubbing attachments or even reply-to munging can break these # signatures. It is generally felt that these signatures have value, even if # broken and even if the outgoing message is resigned. However, some sites # may wish to remove these headers by setting this to 'yes'. remove_dkim_headers: no ``` https://docs.mailman3.org/projects/mailman/en/latest/src/mailman/config/docs/config.html#remove-dkim-headers

== Problem == Emails received from WMIT Mailman may have invalid DKIM signature and are marked as spam. == Context == When someone (with a recent mailserver, I mean a DKIM-enabled mailserver) sends an email to the WMIT Mailman, it may be cases where the original DKIM firm is valid, but Mailman delivers invalid `DKIM-Signature` signature, and so the email is marked as spam and, often, discarded by receivers. This happens because Mailman alters the original message. This happens in various ways: changing the subject, adding the prefix `[Something]`, altering the body, altering the `From:`, etc. Mailman alters the original message and it breaks the original DKIM signature. == Ideal solution == 1. preserve the old DKIM signature in another (non?)standard header (uhm... ?... `X-original-DKIM-Signature:`) 2. delete the sender's DKIM-Signature: since it cannot be valid anymore if Mailman changes the original message 3. just in case, introduce a new DKIM-Signature: header respecting the new message delivered from the mailing list Having said that, I don't think this solution can be implemented easily in Mailman. == Proposed solution == Edit the Mailman configuration file and set `remove_dkim_headers: yes` in order to strip the header `DKIM-Signature:` that usually contains an invalid firm, since the original message was altered by Mailman and so its crypto signature is invalid. Related documentation explaining default value: ``` # Some list posts and mail to the -owner address may contain DomainKey or # DomainKeys Identified Mail (DKIM) signature headers <http://www.dkim.org/>. # Various list transformations to the message such as adding a list header or # footer or scrubbing attachments or even reply-to munging can break these # signatures. It is generally felt that these signatures have value, even if # broken and even if the outgoing message is resigned. However, some sites # may wish to remove these headers by setting this to 'yes'. remove_dkim_headers: no ``` https://docs.mailman3.org/projects/mailman/en/latest/src/mailman/config/docs/config.html#remove-dkim-headers

== Current c== Problem == Emails received from WMIT Mailman may have invalid DKIM signature and are marked as spam. == Context == When someone (with a recent mailserver, I mean a DKIM-enabled mailserver) sends an email to the WMIT Mailman, it may be cases where the original DKIM firm is valid, but Mailman delivers invalid `DKIM-Signature` signature, and so the email is marked as spam and, often, discarded by receivers. This happens because Mailman alters the original message. This happens in various ways: changing the subject, adding the prefix `[Something]`, altering the body, altering the `From:`, etc. == Problem == Mailman alters the original message and it breaks the original DKIM signature. == Ideal solution == 1. preserve the old DKIM signature in another (non?)standard header (uhm... ?... `X-original-DKIM-Signature:`) 2. delete the sender's DKIM-Signature: since it cannot be valid anymore if Mailman changes the original message 3. just in case, introduce a new DKIM-Signature: header respecting the new message delivered from the mailing list Having said that, I don't think this solution can be implemented easily in Mailman. == Proposed solution == Edit the Mailman configuration file and set `remove_dkim_headers: yes` in order to strip the header `DKIM-Signature:` that usually contains an invalid firm, since the original message was altered by Mailman and so its crypto signature is invalid. Related documentation explaining default value: ``` # Some list posts and mail to the -owner address may contain DomainKey or # DomainKeys Identified Mail (DKIM) signature headers <http://www.dkim.org/>. # Various list transformations to the message such as adding a list header or # footer or scrubbing attachments or even reply-to munging can break these # signatures. It is generally felt that these signatures have value, even if # broken and even if the outgoing message is resigned. However, some sites # may wish to remove these headers by setting this to 'yes'. remove_dkim_headers: no ``` https://docs.mailman3.org/projects/mailman/en/latest/src/mailman/config/docs/config.html#remove-dkim-headers