SPF is a system that works as a layer in the mail transfer chain. It defines rules for accepting and rejecting mail based on the source of the message. For example, if an ISP wants to prevent senders from their network from sending emails claiming to be from their customers, they can publish a record giving details of the hosts and networks that are permitted to send messages on their behalf.
If you are using Zimbra to send emails to your customers, here is how you can enable SPF for Zimbra.
Creating an SPF Record for Zimbra
The method for setting up an SPF record for the Zimbra server is simple! To make sure your emails sent using Zimbra don’t fail SPF authentication on the receiver’s side, you need to include the IP address of your Zimbra server in your domain’s SPF record, enlisting it as an authorized sending source.
For the sake of this article, let’s consider the IP address for a Zimbra server to be ip4:x.x.x.x. Please replace it with the unique IP address of your Zimbra server.
Login to your DNS management console
Navigate to Tools & Settings > DNS Template
You need to edit the DNS TXT record related to SPF
An SPF TXT record for Zimbra will have the following syntax:
yourdomain.com TXT v=spf1 ip4:x.x.x.x -all
Publish this record in your DNS records section for your respective domain.
Note: If you don’t have an SPF record previously for your domain, simply publish the above-mentioned record to enable SPF for outgoing emails using Zimbra. If you do have an existing SPF record in your DNS, you need to modify it to include Zimbra, as shown below:
Previous SPF record: v=spf1 mx include:spf.domain.com -all
Modified SPF record: v=spf1 mx include:spf.domain.com ip4:x.x.x.x -all
Wait for 24-48 hours to allow your DNS to process the changes
Finally, you can look up your record using our SPF lookup tool, and enable DMARC for your domains by booking a free DMARC trial to protect your organization against impersonation attacks.