Using more than one SPF record can cause authorization problems. Instead, update an existing SPF record to give permissions to other servers.

For example, if you set up an outbound email gateway, your SPF record includes the Gmail server address and the outbound gateway SMTP server address.

To add a mail server to an existing SPF record, enter the server's IP address before the ~all argument. Use the format ip4:address or ip6:address, as shown in this example:

v=spf1 ip4:172.16.254.1 include:_spf.google.com ~all

To add a mail server’s domain, use an include statement for each domain. For example:

v=spf1 include:serverdomain.com include:_spf.google.com ~all


Set up an outbound mail gateway

An outbound mail gateway server, also known as a smart host, processes email messages before they’re delivered. Typically, outbound mail gateway servers are used for archiving or spam filtering.

Set up an outbound gateway server with G Suite to route all outgoing messages from your domain through a gateway server.

Set up your gateway server

Set up your outbound gateway server to accept and forward email only from G Suite mail server IP addresses. This helps prevent spammers from using your gateway as an open mail relay.

For help on setting up your gateway server, contact the gateway server’s support team.