diff --git a/CHANGELOG.md b/CHANGELOG.md
index b4774fa7..4e42e2b3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -18,6 +18,7 @@
 - **SMTP TLS visualizations had the same cross-product defect as the DKIM/SPF alignment tables** ([#169](https://github.com/domainaware/parsedmarc/issues/169)): `policies` is an object array, and each policy's `failure_details` is itself an object array inside it, so stacking terms aggregations on their subfields cross-products the same way. SMTP TLS documents now also carry `policies_combined` — one `"policy_domain / policy_type"` string per policy — and `failure_details_combined` — one `"policy_domain / policy_type / result_type / sending_mta_ip / receiving_ip / receiving_mx_hostname"` string per failure detail — and documents saved by older versions are backfilled automatically at startup the same non-blocking, idempotent way as the DKIM/SPF backfill; the equivalent manual `_update_by_query` command is documented on the Elasticsearch docs page. Also fixed two adjacent dead fields found while making this change: `_SMTPTLSFailureDetailsDoc` declared `additional_information_uri`, but `add_failure_details` passed it to the constructor as `additional_information`, so it was never actually populated on the declared field; and `receiving_mx_hostname`, which `add_failure_details` has always stored, had no field declaration at all. Both are now correctly wired in the Elasticsearch and OpenSearch outputs.
 - **The Grafana "Map of Message Source Countries" panel's markers now scale with message volume and use a higher-contrast style.** Previously the markers were fixed-size 5 px dots at 50% opacity in dark green, which were nearly invisible on the dark basemap.
 - **Corrected the dead `_SPFResult.results` (plural) field declaration to `result`**, matching what was always written to it.
+- **An mbox-only run no longer shows a misleading, permanently-stuck `0it` progress bar, and mbox parsing now shows a real per-message progress bar on interactive terminals** ([#147](https://github.com/domainaware/parsedmarc/issues/147)). The CLI's progress bar only tracks report files passed directly as arguments — `n_procs` parallel parsing also only applies to those — so runs whose only input was an mbox file displayed an empty bar while messages were parsed sequentially with no visible progress (per-message progress is logged at INFO, hidden in `--silent`/config-file runs). The empty bar is no longer created, `get_dmarc_reports_from_mbox()` now wraps its message loop in a tqdm bar that auto-disables on non-TTY output, and the `n_procs` documentation now states the direct-file-arguments-only scope explicitly.
 
 ## 10.2.4
 
diff --git a/docs/source/usage.md b/docs/source/usage.md
index 9c0017cb..c6a93ea2 100644
--- a/docs/source/usage.md
+++ b/docs/source/usage.md
@@ -169,14 +169,22 @@ The full set of configuration options are:
       any configured output destination fails while saving/publishing
       reports (Default: `False`)
   - `log_file` - str: Write log messages to a file at this path
-  - `n_procs` - int: Number of process to run in parallel when
-      parsing in CLI mode (Default: `1`)
+  - `n_procs` - int: Number of processes to run in parallel when
+      parsing report files passed directly as CLI arguments
+      (Default: `1`)
 
     :::{note}
     Setting this to a number larger than one can improve
     performance when processing thousands of files
     :::
 
+    :::{note}
+    `n_procs` only applies to report files passed directly on the
+    command line. Messages from mbox files and from mailbox
+    connections (IMAP, Microsoft Graph, Gmail API, Maildir) are
+    always processed sequentially.
+    :::
+
 - `mailbox`
   - `reports_folder` - str: The mailbox folder (or label for
       Gmail) where the incoming reports can be found
diff --git a/parsedmarc/__init__.py b/parsedmarc/__init__.py
index b02ea901..2e4cfe5d 100644
--- a/parsedmarc/__init__.py
+++ b/parsedmarc/__init__.py
@@ -34,6 +34,7 @@ import mailparser
 import xmltodict
 from expiringdict import ExpiringDict
 from mailsuite.smtp import send_email
+from tqdm import tqdm
 
 from parsedmarc.constants import (
     DEFAULT_DNS_MAX_RETRIES,
@@ -2126,7 +2127,7 @@ def get_dmarc_reports_from_mbox(
         message_keys = mbox.keys()
         total_messages = len(message_keys)
         logger.debug("Found {0} messages in {1}".format(total_messages, input_))
-        for i in range(len(message_keys)):
+        for i in tqdm(range(total_messages), disable=None):
             message_key = message_keys[i]
             logger.info("Processing message {0} of {1}".format(i + 1, total_messages))
             msg_content = mbox.get_string(message_key)
diff --git a/parsedmarc/cli.py b/parsedmarc/cli.py
index 4d3521bd..2d4ab30c 100644
--- a/parsedmarc/cli.py
+++ b/parsedmarc/cli.py
@@ -2376,7 +2376,7 @@ def _main():
     results = []
 
     pbar = None
-    if sys.stdout.isatty():
+    if sys.stderr.isatty() and len(file_paths) > 0:
         pbar = tqdm(total=len(file_paths))
 
     n_procs = int(opts.n_procs or 1)