Lets assume your domain name is 'myname.com' and your ip address of your server is 1.2.3.4, then you will need the following DNS entries.
| Dns type | Name | Value | Pri |
| A | mail.MYNAME.com | 1.2.3.4 | |
| MX | MYNAME.com | mail.MYNAME.com | 10 |
| TXT | MYNAME.COM | v=spf1 ip4:1.2.3.4/24 a mx -all |
Also you should ask your ISP provider setup a reverse DNS ip name so that 1.2.3.4 -> mail.MYNAME.com