After reading this post, I got a bit worried because DKIM breaks every two SM releases and checked our log. We found this;
(cropped because there are a lot of occurences)
[2022.10.11] 00:35:07.313 [56967766] Exception getting DKIM signature System.ArgumentException: The list of headers to sign SHOULD NOT include the 'Bcc' header.
[2022.10.11] 00:35:07.313 [56967734] Exception getting DKIM signature System.ArgumentException: The list of headers to sign SHOULD NOT include the 'Bcc' header.
[2022.10.11] 00:35:07.313 [56967754] Exception getting DKIM signature System.ArgumentException: The list of headers to sign SHOULD NOT include the 'Bcc' header.
[2022.10.11] 00:35:07.313 [56967744] Exception getting DKIM signature System.ArgumentException: The list of headers to sign SHOULD NOT include the 'Bcc' header.
[2022.10.11] 00:35:07.313 [56967774] Exception getting DKIM signature System.ArgumentException: The list of headers to sign SHOULD NOT include the 'Bcc' header.
[2022.10.11] 00:35:07.313 [56967764] Exception getting DKIM signature System.ArgumentException: The list of headers to sign SHOULD NOT include the 'Bcc' header.
[2022.10.11] 10:32:31.926 [56996996] Exception getting DKIM signature System.ArgumentException: The list of headers to sign SHOULD NOT include the 'Bcc' header.
[2022.10.11] 16:54:07.242 [57029773] Exception getting DKIM signature System.ArgumentException: The list of headers to sign MUST include the 'From' header.
[2022.10.13] 10:18:37.668 [57157599] Exception getting DKIM signature System.ArgumentException: The list of headers to sign MUST include the 'From' header.
[2022.10.13] 14:47:59.495 [57180148] Exception getting DKIM signature System.ArgumentException: The list of headers to sign SHOULD NOT include the 'Bcc' header.
[2022.10.13] 14:48:02.495 [57180151] Exception getting DKIM signature System.ArgumentException: The list of headers to sign SHOULD NOT include the 'Bcc' header.
[2022.10.13] 14:49:42.139 [57180271] Exception getting DKIM signature System.ArgumentException: The list of headers to sign SHOULD NOT include the 'Bcc' header.
[2022.10.13] 14:49:42.139 [57180266] Exception getting DKIM signature System.ArgumentException: The list of headers to sign SHOULD NOT include the 'Bcc' header.
[2022.10.13] 14:51:03.624 [57180383] Exception getting DKIM signature System.ArgumentException: The list of headers to sign SHOULD NOT include the 'Bcc' header.
[2022.10.13] 14:51:03.640 [57180385] Exception getting DKIM signature System.ArgumentException: The list of headers to sign SHOULD NOT include the 'Bcc' header.
I checked the DKIM settings for some of these. The one with missing from is configured like this:
The others complaining about BCC field is configured like this:
I see that we're not consistant about which headers to use for the signing but:
1) Shouldn't the "All non-repeatable fields" option include the From header field ? (as it causes an exception if it is missing)
EDIT: Maybe the mail being signed is missing a "From" header, I have to check this deeper.
2) Shouldn't SM automatically dismiss the BCC field for signing, when using other options (as it will cause an exception)
EDIT: I tried to reproduce the error in the log by sending mails with BCCs but without luck so far
Kind regards,
Sébastien