Desk don't send message proprely. the customer receive a message from an address with "via desk-mailer.zohodesk.eu"

Desk don't send message proprely. the customer receive a message from an address with "via desk-mailer.zohodesk.eu"

Hello,

I don't resolve the following problem.
I have a department address configured : helpdesk@domain.com
This address is also configured in From address 
Everything works well except when Zoho responds to a new message arrived by mail or for agent notifications or customer portal invitation.

On the over hand, the mails sent by the agent after ticket is opened arrived with correct smtp header !

But for the client notification of new ticket for instance, the client received a mail with 
Company Helpdesk via desk-mailer.zohodesk.eu 
instead of 
Company Helpdesk

in "from" header. It is not nice !

I worked around a lot, waited 2 days for propaging dns to Google and MS but nothing !

The SPF record of my company seems to be ok to accept mail from zohodesk.eu . here is the domain spf :
v=spf1 include:spf.messagelabs.com include:spf.protection.outlook.com include:spf.zohodesk.eu include:spf.zoho.com ~all

A inspected the smtp header of the message sent by zoho:
From: Company Helpdesk <helpdesk@company.com>
Sender: helpdesk=domain.com@desk-mailer.zohodesk.eu
To: xxx@gmail.com
Message-ID:

From and Header are differents
Why Zoho don't use SMTP server configured in "From address" Email channels to send mails for new ticket, Agent notification and portal invitation
Thanks for your help