Hello Nishant,

Thanks to replay. 

my xml code look like this (each email separated by comma):

<field name="email_to">${(object.user_id.email or '')|safe}, ${(object.partner_id.email or '')|safe}</field>

When launching the email template form, the email address is visible in recipients fields (it's look like everything is ok - there are two email destination)

The problem is, only the last email address that receive email

Hello,

email_to:

Inside email_to you can enter email addresses saperated by comma.

partner_to:

Inside partner_to you need to enter partner ID saperated with comma so email will be send to email address of enterd partner IDS.

Hope this will be helpful.