I don't want to setup DKIM, SPF and to do SMTP authentication ; an hosting-provider-email-box solves this but what if I want a domain-registrar-email-box instead?

On a shared hosting (CentOS-Bash) I have a website with a backend (PHP) - frontend CMS-agnostic contact form.

I need to transfer emails sent via this contact form directly to an email address (I don't save anything in my website's database).

I don't want to setup DKIM, SPF and to do SMTP authentication because for me it's an overkill --- I don't send emails to anyone from my website domain - but to myself. I also don't want to use PHPmailer ; I use a simple PHP mail() directive set.

If I create an email address on my hosting provider's end than I should have no technical problem;
The hosting domain and the website domain will match, DKIM/SPF are set and SMTP/MTA are configured and I could also have an aesthetic address such as info@example.com without fearing that such an address being already in use in generally every third party email service provider.

At least I might want to use third party email provider.

• Large-gratis email service providers such as Baidu, Gmail, Hotmail and Yandex are quite strict in their spam or alleged-as-spam filtering and I am afraid that if I would work with one of them but would make even the slightest configuration mistake on my hosting environment (and I think there is a lot to configure with emails and much potential for mistakes) I could lose many potential customers.

• I thought about buying an email box from my domain registrar, than I could also have an aesthetic name such as info@example.com without such an address being already in use but my main problem with that approach is that I don't know what to expect; my domain registrar is also a huge company with potentially millions of customers and might have ardent spam or alleged-as-spam filtering so buying an email address from it might end in similar problems to those I could experience with the large-gratis email service providers such as those mentioned above.

Can I still easily use an email address outside of my hosting account domain (in this case, in my domain registrar)?

"easily" here means "without configurations at all - something that 'just works'".