diff --git a/docs/content/config/environment.md b/docs/content/config/environment.md
index e209a0cf..1d378e3f 100644
--- a/docs/content/config/environment.md
+++ b/docs/content/config/environment.md
@@ -247,6 +247,12 @@ Set the mailbox size limit for all users. If set to zero, the size will be unlim
 
 See [mailbox quota][docs-accounts-quota].
 
+!!! info "Compatibility"
+
+    This feature is presently only compatible with `ACCOUNT_PROVISIONER=FILE`.
+
+    When using a different provisioner (or `SMTP_ONLY=1`) this ENV will instead default to `0`.
+
 ##### POSTFIX_MESSAGE_SIZE_LIMIT
 
 Set the message size limit for all users. If set to zero, the size will be unlimited (not recommended!). Size is in bytes.
diff --git a/target/scripts/startup/variables-stack.sh b/target/scripts/startup/variables-stack.sh
index 3d0d1bee..dc7fb450 100644
--- a/target/scripts/startup/variables-stack.sh
+++ b/target/scripts/startup/variables-stack.sh
@@ -106,7 +106,6 @@ function __environment_variables_general_setup() {
   VARS[ENABLE_POP3]="${ENABLE_POP3:=0}"
   VARS[ENABLE_IMAP]="${ENABLE_IMAP:=1}"
   VARS[ENABLE_POSTGREY]="${ENABLE_POSTGREY:=0}"
-  VARS[ENABLE_QUOTAS]="${ENABLE_QUOTAS:=1}"
   VARS[ENABLE_RSPAMD]="${ENABLE_RSPAMD:=0}"
   VARS[ENABLE_RSPAMD_REDIS]="${ENABLE_RSPAMD_REDIS:=${ENABLE_RSPAMD}}"
   VARS[ENABLE_SASLAUTHD]="${ENABLE_SASLAUTHD:=0}"
@@ -115,6 +114,15 @@ function __environment_variables_general_setup() {
   VARS[ENABLE_SRS]="${ENABLE_SRS:=0}"
   VARS[ENABLE_UPDATE_CHECK]="${ENABLE_UPDATE_CHECK:=1}"
 
+  # The Dovecot Quotas feature is presently only supported with the default FILE account provisioner,
+  # Enforce disabling the feature, unless it's been explicitly set via ENV (to avoid mismatch between explicit ENV and sourcing from /etc/dms-settings)
+  if [[ ${ACCOUNT_PROVISIONER} != 'FILE' ]] || [[ ${SMTP_ONLY} -eq 1 ]] || [[ ${ENABLE_QUOTAS} -neq 1 ]]; then
+    _log 'debug' "The 'ENABLE_QUOTAS' feature is enabled by default but is not compatible with your config. Disabling"
+    VARS[ENABLE_QUOTAS]="${ENABLE_QUOTAS:=0}"
+  else
+    VARS[ENABLE_QUOTAS]="${ENABLE_QUOTAS:=1}"
+  fi
+
   _log 'trace' 'Setting IP, DNS and SSL environment variables'
 
   VARS[DEFAULT_RELAY_HOST]="${DEFAULT_RELAY_HOST:=}"