Email Server; How to configure postfix to suit my needs? (Do I need SASL or/and TLS?)

Question

I have a linux server, where I just installed postfix.

I have done nothing more with the email server config.

My website is a classifieds website, where users may put ads, delete ads etc etc. No login and no member functions at all.

Only place I need to use email is this:

• When posting a new classified a confirmation email will be sent out
• When deleting a classified a confirmation email will be sent out
• When contacting the support
• users are able to email the seller by clicking "email seller" and filling out a form.

My Q is, how should I configure Postfix?

Do I need SASL, and TLS? What else do I need to know?

Btw, PHP is used to mail...

Answer 1

Your server is only used for submission, sending locally generated mails out. Therefore you don't need sasl for authenticating senders. You also don't need TLS to receive mails.

BUT you may need them to send them out. E-Mail sending has become a bit trickier than in the early days with the problem of spam. Many smtp receivers won't accept mails from hosts that are not associated with the domain (MX record, SPF etc)

You probably want to have a smart host that is responsible for sending mails for your domain. You set up postfix (transport map) that all mail gets sent to that smart host. This host may want to authenticate your postfix with SASL or may only accept TLS connections for submission. (It may also just authenticate by your IP address, but that is not recommended.)

You also have to think about the From address in your mail if you are sending on behalf of users. Do you want to use their email address as sender? This is hard, since many mail hosts won't accept them for the reasons stated above.

You also need to know where to send failed deliveries of mail (just delete them? Send them to your mailbox with the error report).

Answer 2

Also, install dkim and domain-keys