Sender Policy Framework (SPF) Records are used to validate the sources of sent email for a domain to ensure they are legitimate messages and not spam. SPF Records are configured on your authoritative DNS server in the configuration settings and are a necessary requirement to successfully use our Email-to-fax service. Our Email-to-fax service has several steps that must complete for success and if the SPF Record check fails, the process stops and the fax you are attempting to send will fail.
The first thing you will need to determine is the number of SMTP servers that will be sending as @yourdomain.com. For example, if lisa@yourdomain.com is sending via Comcast SMTP servers (smtp.comcast.net), your SPF record will need to include IP 68.87.26.155; or to put it in context, ip4:68.87.26.155 (Comcast SMTP Server IP address). Additionally, if there are IP ranges in which mail can pass through, you will need to add those appropriate ranges. This information can typically be obtained through your email provider or system administrator if you do not readily have this information available. An IP range will have a forward slash at the end of the IP address. For example, Google's SPF Record has this range: ip4:74.125.0.0/16.
The most common (easiest) entries you will need for your SPF records will closely mimic example below:
v=spf1 mx ip4:64.136.174.217 ip4:64.136.173.84 a:titaniumvfax.com ~all
(The IP address above are examples only. They must be changed to the IP address if your mail server).
*Once you have configured your SPF Record, you will need to allow time for it to propagate. The amount of propagation time is determined by the Time To Live (TTL) parameter you have configured in the server. Do not expect a previously failed SPF Record to take immediate effect once you have updated the record. The new record will not update until the current TTL has expired. There are a few tools available to check an SPF record, ond such tool is MX Toolbox. When using this site, you will need to enter the domain for which you are checking the SPF Record (for example, google.com) and click the 'MX Lookup' button to get the results.