docs(garuda-mail): update information with current changes

docs/src/hosts/garuda-mail.md

@@ -2,24 +2,50 @@
 
 ### General
 
-This system mainly consists of the [simple-nixos-mailserver](https://gitlab.com/simple-nixos-mailserver/nixos-mailserver). Its only purpose is providing a mail service to team members. The current config looks like [this](https://gitlab.com/garuda-linux/infra-nix/-/blob/main/nixos/hosts/garuda-mail.nix?ref_type=heads#L47).
+This system mainly consists of the [simple-nixos-mailserver](https://gitlab.com/simple-nixos-mailserver/nixos-mailserver).
+Its only purpose is providing a mail service to team members.
+The current config looks like [this](https://gitlab.com/garuda-linux/infra-nix/-/blob/main/nixos/hosts/garuda-mail.nix?ref_type=heads#L47).
 In case of issues, the [documentation](https://nixos-mailserver.readthedocs.io/en/latest/) can be consulted.
 
 ### Mail server setup
 
 The mail server details are as follows:
 
 - host: `mail.garudalinux.net`
-- incoming: IMAP via `993`
-- outgoing: SMTP via `587/465`
+- username: full email address
+- password: given password
+- incoming: IMAP via `993` (SSL)
+- outgoing: SMTP via `587/465` (STARTTLS/SSL)
+
+Additionally, it is possible to make use of the [Roundcube-powered web interface](https://mail.garudalinux.net).
+
+### Roundcube
+
+Roundcube is used to provide a web interface for our mail accounts.
+It features a few plugins to enhance the general user experience.
+
+#### Plugins
+
+- attachment_reminder - reminds about forgotten attachments
+- authres_status - checks for whether SPF/DKIM/DMARC match the sending domain
+- carddav - allows adding a CardDAV contact book as source (eg. Nextcloud)
+- contextmenu - adds a right click context menu to the most pages
+- custom_from - allows customizing from address
+- managesieve - allows managing Sieve rules, which automatically sort incoming mails based on rules
+- newmail_notifier - new mail notifier for desktops
+- persistent_login - alows storing a persistent login cookie for no more login prompts
+- thunderbird_labels - shows Thunderbird labels
+- zipdownload - allows downloading all attachments at once
 
 ### Backups
 
 Backups are happening daily via Borg. A Hetzner storage box is used to store multiple generations of backups.
 
 ### Creating a new user
 
-A new user can be created be adding a new `loginAccounts` value and supplying the password via `secrets`. We make use of `hashedPasswordFile`, therefore new hashes can be generated by running `nix-shell -p mkpasswd --run 'mkpasswd -sm bcrypt'`. Add it to the `secrets`, `deploy` and `apply`. Don't forget to commit both changes.
+A new user can be created be adding a new `loginAccounts` value and supplying the password via `secrets`.
+We make use of `hashedPasswordFile`, therefore new hashes can be generated by running `nix-shell -p mkpasswd --run 'mkpasswd -sm bcrypt'`. Add it to the `secrets`, then execute `deploy` and `apply`.
+Don't forget to commit both changes.
 
 ### Nix expression