chore: add mail section

docs/ecolyo/Technical/mail.md

@@ -82,3 +82,20 @@ A bounce token stored in the profile of each user is sent in email. It allows us
 ## Unsubscribe
 
 A user can unsubscribe to our newsletter by a link in each mails. It **does not** require authentication. This link is built with a `sharecode` token that contains specific permissions to turn off the `sendAnalysisNotification` property in the user profile. The sent link has a TTL of 15 days.
+
+## Mail server
+
+The mail server is configured with the [`cozy.yml` under the mail section](https://github.com/bastiendmt/cozy-stack-compose/blob/main/files/cozy.yml#L36).
+
+The mail server is `mail.alpha.grandlyon.com`. It's IP is 51.15.131.84. This server is managed by Scaleway.
+
+It also has a web interface accessible at [https://mail.alpha.grandlyon.com/](https://mail.alpha.grandlyon.com/).
+
+### Reboot in case of failure
+
+```sh
+cd /opt/mailcow-dockerised
+docker-compose down
+docker volume rm mailcowdockerized_clamd-db-vol-1
+docker-compose up -d
+```