odoo 9.0 CE
addons/mail/models/mail_thread.py in method message_get_reply_to
This function compares the parent model ids set on odoo>settings>technical>email>aliases with the computed model name via
model_name = self.env.context.get('thread_model') or self.name
When sending a message via sales leads model_name evaluates to crm.team. So to get the alias right you need to set the parent model in odoo settings to Sales Teams.
On the other hand, when sending a message via contacts, model_name evaluates to res.partner. Is there anything I can set in Odoo FE to make this crm.team instead?