Creating email addresses

Hi,

I wanted to know the easiest way and what is needed in order to setup receiving email addresses on my droplets. (And some users need to also be sending from their email)

I’m not looking to manage any email servers. But I do want to create email addresses. For instance.

user1@domain.com user2@domain.com user3@someotherdomain.com etc.

I am aware of the security implications of maintain our own mail server so that is why I’m not looking forward to host it locally.

I also want it to be easy to create new incoming addresses. I want to easily manage the addresses created on the domain. I need my Apps, like Wordpress for instance (contact form, registrations confirmation, password reset, etc), to be able to send email from the server. Some users need to send out email from their @domain.com address. I could forward aliases to some external addresses (like @gmail, @hotmail, etc) but then how would those users be able to send from their @domain (I think it’s not possible, am I wrong?)

If I just want to create aliases, do I need Postfix? If I just want to forward aliases to external emails, do I need Postfix? If I install Postfix on my server to forward aliases to external email addresses, do I risk Spoofing attacks from the @domain.com addresses ?

I know it a lot of questions but I’m trying to figure out the easiest, reliable and secure way to create and manage email addresses for any given domain without having to specifically maintain a mail server. If that is the only solution, please advise so :)

Thanks in advance