[sdnog] PTR and SPF records

[Sara Alamin]

Good morning All,

I've some questions about the PTR and SPF records in DNS 
- Is the PTR  record is not necessary for the mail system ? I can just define MX and A record for it ?
- Can  I configure only spf record  to let  the recipient email servers know what is my  SMTP Email server ? in other word  Can I use SPF record  as a replacement for PTR ?

Thanks in advance.
Regards,
--Sara Alamin--