TechNestCustomers judge the sender before they read the paragraph. A message from a shared free mailbox says the firm has not finished its address. The words can be careful and still look temporary.
The address is part of the offer
info@, sales@ or the person's name at the firm's domain belongs on the invoice, the site footer and the reply. One domain can hold several boxes. The disk they use is part of the hosting account, so the size of attachments belongs in the same plan as the site.
What to open first
Open the mailbox you will actually answer. An unused hello@ that nobody checks is worse than no address, because customers write and wait. Put the same address in the contact page. Business mail sits with the domain. The domain shelf is where the name starts.