In Odoo 15, there is a built-in feature that allows you to attach documents from the CRM record to an email message without having to download them to your computer first. Here are the steps to do this:

Go to the CRM record that contains the documents you want to attach to an email message.

Click on the "Messages" tab to open the message thread.

Click on the "Send a message" button to open the message window.

In the message window, click on the "Add an attachment" button.

In the "Add attachment" dialog, click on the "Record" tab.

Select the CRM record that contains the documents you want to attach.

In the "Documents" tab, select the documents you want to attach to the message.

Click on the "Attach" button to add the selected documents to the message.

Compose your email message as usual and click on the "Send" button to send the message with the attached documents.

By following these steps, you should be able to attach documents from the CRM record to an email message without having to download them to your computer first. This should save you time and effort, especially when dealing with multiple attachments.

Hi Waymark,

Thanks for your reply. 

Nope, on my computer using either Chrome or Safari it doesn't look like you described it. Clicking either the tiny paperclip symbol or the button "Attach a file" when in full composer view mode displays no such thing as a Record tab. It only displays a normal file selector dialog. I am on a Mac, could this be a macOS thing?

Any ideas?

Hello there; I'm facing the same situation. What it worked for me is to create an e-mail  then save it as a template with the attached files; then, any new e-mail used with such template will contain the attached files.

p.s. I'm working on Odoo online v. 17

Hello Stefan Rundgren,

You’re not able to attach already available documents in email(Send message) cause the widget ‘many2many_binary’ is applied on field “Attachments”.

To achieve your goal you can change or remove the widget ‘many2many_binary’ from field Attachment.

And also you can inherit Email composition wizard as shown in below example to add Attachments field after/below the button ‘Attachments’ and you can select the documents attached to CRM lead/opportunity from that.

Please find code in comment. 

hope this can help you.

Thanks & Regards,
Email: odoo@aktivsoftware.com
Skype: kalpeshmaheshwari