It is important to choose a sender email that clearly identifies you.
The part before the arobase should reassure the user as to the identity of the sender and the nature of the emails. (e.g. communication@; email@; newsletter@; contact@; etc.).
The part after the arobase is generally the domain name you use to host your site. It enables users to identify you quickly.
You can also create a sub-domain dedicated to your email marketing campaigns in order to better control your e-reputation. Your domain name probably sends other emails from other platforms (transactional emails, internal communications, professional emails, etc.).
It's up to you!
