diff --git a/docs/email.md b/docs/email.md
new file mode 100644
index 0000000..93587f1
--- /dev/null
+++ b/docs/email.md
@@ -0,0 +1,36 @@
+# Email
+
+All email is stored on a GCP instance, which runs Postfix and Dovecot.
+
+This host receives all email for both `chriscowley.me.uk` and `cowley.tech`, but does not forward/send them.
+
+!!! note "Why not send through this host?"
+
+    First, GCP block outgoing SMTP connections on several ports. Second, email forwarding is based on reputation and I can't be bothered to deal with it.
+    
+For a long time I used [Mailjet](https://app.mailjet.com) for sending emails, but then switch to [SMTP2Go](https://smtp2go.com) because it allows more key/secret pairs. These need to be configured on the clients (Thunderbird, Evolution, phone, whatever).
+
+## TLS Certificates
+
+Managed using LetsEncrypt using a really simple script:
+
+```bash
+/root/renew_certs.sh
+```
+
+It runs daily to renew all certs on that host
+
+
+## Backup
+
+Backups use [Restic](https://restic.readthedocs.io/en/stable/) and are stored in Backblaze B2. The bucket is called `instance2-backup`.
+
+There are 2 scripts for the backups:
+
+```bash
+/usr/local/bin/clean-backup
+/usr/local/bin/run-backup
+```
+
+The backup is run every day and the clean up runs once a week.
+
diff --git a/mkdocs.yml b/mkdocs.yml
index 8c5b8cb..a747b67 100644
--- a/mkdocs.yml
+++ b/mkdocs.yml
@@ -63,6 +63,9 @@ plugins:
   - social
 
 markdown_extensions:
+  - admonition
+  - pymdownx.details
+  - pymdownx.superfences
   - footnotes
   - pymdownx.superfences:
       custom_fences: