Hi Odoo Dev,

I'd like to underscore the need for true "multi-recipient" emails being sent from Odoo. This means that when multiple comma separated email addresses are used in the To: or CC: configuration then the email should be constructed to have both/multi recipients on the same email.

Condition: 3 comma separated addresses in the To field and 2 addresses in the CC field. (doesn't matter if in a template or on a Send Message custom email, should support either listed partner ids or email addresses)
Expected Result: The same one email with 5 addressees on it would get sent 5 times to the different recipients.
Actual Result in Odoo: 5 different emails will get sent with each addressee being the sole To: recipient. There isn't any indication that the email was sent to 4 other people. 

• I've heard at some point that the development stance is "this is our way and we think it's superior and we're going to stick with it."
• I think it's time to ask you to reconsider your stance. Please look at all major email and webmail clients. They all offer functionality as described in the Expected Result. When there is a worldwide accepted UX pattern then it is a poor user experience when you use the same UI elements but offer a different outcome.
• What you have implemented is essentially Blind CC, and I have seen many cases over the years where it causes problems. The most common example is when I (or my clients) send an invoice. The majority of cases there is a human contact that would like to see the invoice and also an accountspayable@ email address that goes to accounting. (or bill digitization in Odoo!) Over and over and over again I get a response from the human contact saying "you should also send this to accountspayable@" or you won't get paid. In Odoo I have done that already, but since they can't see that on the email they don't know. My clients complain of this too.
• This has been an issue I have been aware of since 2021. You can see in this forum post I have suggested a code workaround to list everyone who is receiving the email in the body of the email. However this is not usually enough. People are used to looking at the header of their emails and seeing who is cc'd and addressed.
• People are also very used to reply-all functionality in their email clients. Your current blind-cc approach makes it impossible for someone to reply-all.
• In the invoice example above, many times the main point of contact is asked to approve the invoice for payment. If the invoice email were a true multi-recipient email, then their reply-all saying "invoice approved" would go to the accountspayable@ distro and keep the process moving. However with the BCC approach used by Odoo the reply can only go back to the reply@odoo.com and the message will get tagged on the invoice transaction, but the accountspayable@ distro would not see the approval. Thus causing delays and friction.

I'm sure there are some difficulties in executing this upgrade and ensuring it works reliably, but it's time to get it on the roadmap. I also suggest making this a configurable option on a per-DB or per-template basis. There may be some cases where companies have gotten used to the BCC approach and won't want to change immediately.

One more while we are here. There should be an option on templates to "not automatically send to all followers." Clients/Customers get added automatically to transactions as followers in many cases, like on sent sales proposals. However there may be cases where an email should be generated and sent internally and not to the customer. There should be a way to build a template without sending to the followers.

Feedback always appreciated!