Create a Sender Policy Framework (SPF) DNS record to authorize IP addresses and mail servers allowed to send email on behalf of your domain.

Domain Name

Policy Strictness (All Mechanism)

Authorize MX Servers (Allow domain's incoming mail servers to send mail) Authorize A/AAAA Records (Allow domain's main web server IP to send mail)

Authorized IPv4 Addresses / Subnet Ranges (One per line or comma-separated)

Authorized IPv6 Addresses / Subnet Ranges (One per line or comma-separated)

Authorized External Domains / Include Blocks (One per line or comma-separated)

DNS Record Name / Host @ (or blank)

DNS Record Type TXT

v=spf1 a mx ~all

SPF Record Generator - iN2 LLC