Email notifications fail if duplicate headers exist

[wusel (Kai 'wusel' Siering)]

Oh, nice — yes, it does:

So, if I understand this correctly,

 433    def header_value(name)
 434      header = @message.header[name]
 435      return nil unless header
*436      header.value
 437    end

is – in the Discource code? – where Sidekiq bails out?

This is called from …

 228      MessageBuilder.custom_headers(SiteSetting.email_custom_headers).each do |key, _|
*229        value = header_value(key)
 230
 231        # Remove Auto-Submitted header for group private message emails, it does
 232        # not make sense there and may hurt deliverability.

So it could be a custom header?

I indeed do have an entry there:

I’ve reset this to defaults, and … actually it seems that email notifications are indeed been sent out again, as verified by readers.

Thanks!

One question remains, though: Why is »Auto-Submitted: auto-generated|Precedence: bulk« causing this failure? It states that custom headers shall be seperated by »|«.