feat: added the script that was used to get stuff abck online after Nixos Mailserver migration 3

mail/migration3_cleanup.sh

@@ -0,0 +1,16 @@
+#!/usr/bin/env bash
+
+# After running Migration 3 (https://nixos-mailserver.readthedocs.io/en/latest/migrations.html#dovecot-mail-directory-migration)
+# For some reason dovecot was putting items into /var/vmail/ldap/$USERNAME@skynet.ie instead of /var/vmail/skynet.ie/$USERNAME
+# Whats more it was expecting to see items there so email clients were erroring out (seeing empty inboxes).
+# This could be due to the extra commits we have on top of the main nixos mailserver
+# This might be the case since migration 2 mentions teh /var/vmail/ldap folder as not being desired
+
+for f in *; do
+    if [ -d "$f" ]; then
+       echo "$f"
+       mkdir -p "/var/vmail/ldap/$f@skynet.ie/"
+       # hardlink "copy", can delete the original folder afterwards
+       cp -rlp /var/vmail/skynet.ie/$f/* "/var/vmail/ldap/$f@skynet.ie"
+    fi
+done