diff --git a/docs/setup-guide.rst b/docs/setup-guide.rst
index e6ef029..00f8aae 100644
--- a/docs/setup-guide.rst
+++ b/docs/setup-guide.rst
@@ -122,18 +122,18 @@ Set a ``SPF`` record
 Add a `SPF <https://en.wikipedia.org/wiki/Sender_Policy_Framework>`_
 record to the domain ``example.com``.
 
-================ ===== ==== ================================
+================ ===== ==== ================
 Name (Subdomain) TTL   Type Value
-================ ===== ==== ================================
-example.com      10800 TXT  `v=spf1 a:mail.example.com -all`
-================ ===== ==== ================================
+================ ===== ==== ================
+example.com      10800 TXT  `v=spf1 mx -all`
+================ ===== ==== ================
 
 You can check this with
 
 ::
 
    $ nix-shell -p bind --command "host -t TXT example.com"
-   example.com descriptive text "v=spf1 a:mail.example.com -all"
+   example.com descriptive text "v=spf1 mx -all"
 
 Note that it can take a while until a DNS entry is propagated.