How to configure Postfix for Forum?

Question

linux

Need SMTP for forum. I can’t find simple instructions, they write everywhere how to create a full-fledged mail server. In the meantime, I need SMTP for SimpleMachines so that it can send emails to activate the account.

Answer 1

1. Buy a second-level domain (preferably - it's easier).
2. Buy an external IP from your provider
3. Open port 25 on your server and forward this port from the external IP to your server. Or just open if the server looks directly outside.
4. Install any SMTP agent on the server. You can postfix, and exim, and anything else. At least sendmail. By the way, the latter is generally gorgeous for your purpose - it is extremely easy to set up.
5. On your hosting or where you delegated your domain, register 4 DNS records: A - to indicate that this IP is on this address; MX - Here the address of the mail domain is bound to the real address of the server (to the A record). For example, you bought the domain.com domain, and the server name is mail.domain.com. So the A record for this server would be "123.456.789.012 mail.domain.com" and the MX record would be "domain.com mail.domain.com". There are still concepts of priorities, but google it. Everything is simple there.
Next, configure the PTR and SPF DNS record there. PTR - This is a record, the reverse of A. It serves to check the validity of your server (from the side of the mailer), but in general it is needed so that you can find out the server name by IP. Without it, letters from your server will either not be accepted by other mailers at all, or will be sent to spam. And even completely weeded out. And last but not least, SPF. This is a TXT format record. You can also easily find descriptions on the Internet.
Now for the instructions.
Postfix
Exim: here and here is
Sendmail

Answer 2

in order for the letters you send not to fall into spam and reach your users, you need to set up a full-fledged mail server on your domain.

Answer 3

raise sendmail, there are a lot of instructions for centos, it rises very quickly. And everything will work for you.