Hello Everyone. 

I dont understand the relationship between the sales team email address and the user that i have added to the sales teams email address. 

So i created a user called user@mycompany.com 
the sales team use the email sales@mycompany.com

i tested to create a quotation and everything seems to be alright but no email is being sent. 
I checked the outgoing emails settings and notice that the email have not been sent and it has the error

Mail Delivery FailedMail delivery failed via SMTP server 'send.mycompany.com'. SMTPRecipientsRefused: {'testcontact@mycompany.com': (554, '5.7.1 <testcontact@mycompany.com>: Recipient address rejected: Username sales@mycompany.com and sender postmaster-odoo@mycompany.com doesnt match')}

I cant find where Odoo is grabbing the email "postmaster-odoo@mycompany.com"

i guess its a missmatch with the user i created "test@mycompany.com" and the sales teams email. But i do not know how to tell that the when the user user@mycompany.com is sending quotations, orders and invoice it should use sales@mycompany.com :) ? 

Can someone help where i need to troubleshoot. 

BR

Emil