Force emails not to be grouped into conversations

Question

My website sends emails to me with the same subject and they are being grouped into conversations even if I delete old ones (Mail, Gmail). I know I can change the subject to prevent this, but is there a header or something else that can be added to do this without forcing unique subject lines?

Blockish

gmail grouping infuriates me. Maybe I am too old school and like to read oldest to newest. I don't get gmail grouping. – Colorless

ojblass, it can be turned off in your preferences. But I need something that works from the sending side. – Blockish

Answer 1

On the top of my head, there are two methods to avoid threading:

• set the SMTP header X-Entity-Ref-ID with any value. This is what Google+ notifications do.
• change the sender email (you can use From: [email protected]). This is what Facebook notifications do.

The threading will be made if you force it with Reference or Reply-To.

Jeffjeffcoat

YES! Wow, this is saving me a ton of hair-pulling. All the other answers I found to this question were adding random numbers to subject lines - I don't want to send that to my users! And GMAIL destroys the css on my HTML emails. THANK YOU RDS! – Equi

Wow, thanks for this but, how do you know about X-Entity-Ref-ID ? is it a gmail only thing ? I can't find anybody else talking about this in the internet :) – Turbid

X- are private fields, so this one is likely to be Gmail specific only. – Jeffjeffcoat

The SMTP headers are visible in any message. – Jeffjeffcoat

The X-Entity-Ref-ID did not work for me; +randomstring did! Thx. – Gentlemanfarmer

For me X-Entity-Ref-ID: null did work, both for GMail as well as a client like Airmail. – Teagan

Oh my god - thank you so much for that X-Entity-Ref-ID trick! Been pulling my hair out with this issue for two days. – Assumed

Answer 2

The situation has changed since 2019.

I found a solution in https://workspaceupdates.googleblog.com/2019/03/threading-changes-in-gmail-conversation-view.html.

Setting a header of the form References: <[email protected]>, with a unique UUID for each email is enough to solve this.

Tested a few times today and I confirm it works.

Chatty

Unsure if it works – I get emails threaded even in the absence of an X-Entity-Ref-ID header. Just same title and sender seem enough. – Steal