Sender Policy Framework (SPF) records are created in order to prevent spammers from sending mails on behalf of your domain. An SPF record is a type of DNS record (TXT) which specifies the IP address or addresses that are authorized to send emails for the specific domain.
Important Note: most anti-spam systems have SPF check enabled and will reject your messages unless an SPF record exist for your domain.
Create the SPF record
Login to your hosting provider’s DNS control panel and create the following TXT record.
Hostname: your domain (e.g. yourdomain.com)
Record Type: TXT
TXT Value: v=spf1 ip4:18.104.22.168/32 ip4:22.214.171.124/32 -all