# Email notifications fail if duplicate headers exist **URL:** \ **Category:** Bug\ **Created:** [April 2, 2022, 9:33pm UTC](https://meta.discourse.org/t/email-notifications-fail-if-duplicate-headers-exist/222960 "2022-04-02T21:33:09Z")\ **Posts on this page:** 1\ **Showing post:** 13
**Author:** ![wusel](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/wusel/32/255451_2.png) [@wusel](https://meta.discourse.org/u/wusel)\ **Post date:** [April 12, 2022, 10:08am UTC](https://meta.discourse.org/t/email-notifications-fail-if-duplicate-headers-exist/222960/13 "2022-04-12T10:08:00Z")
Oh, nice — yes, it does: ![Screenshot 2022-04-12 at 11-13-26 Logs](https://global.discourse-cdn.com/meta/original/4X/5/4/f/54f3bdc5f28818243c66526a9c745e9dbf1cf8c8.png) So, if I understand this correctly, ```plaintext 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 … ```plaintext 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: ![Screenshot 2022-04-12 at 11-27-31 Administration - Freifunk Kreis GT](https://global.discourse-cdn.com/meta/optimized/4X/e/7/c/e7c659db260c0b4b1a9382a364eae4266ea6e755_2_690x59.png) 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 »|«. --- _[View the full topic](https://meta.discourse.org/t/email-notifications-fail-if-duplicate-headers-exist/222960)._