A database that has been live for a while ends up with dozens of email templates, and nobody can tell which ones still matter. Odoo cannot tell you either: core keeps no link at all between a sent email and the template that produced it — neither mail.mail nor mail.message has a template field, on any version from 14.0 to 19.0. This module adds that link, records every send as it happens, and turns it into a read-only report: one line per template, with how many emails it produced, when it was last used, whether it was customised since installation, and whether an automated action points at it. Free and open source (LGPL-3), Odoo 14.0 through 19.0.

• Emails produced, first used, last used — counted when the message is created, so the figures survive Auto Delete, which erases the evidence of the most heavily used templates seconds after sending.
• Still stored — how many outgoing mails and chatter messages produced from the template are still in the database, with buttons on the template's form to open them.
• Where it came from — shipped by a module (with the module name) or created in this database.
• Customised since installation — flagged when the template was edited after the module that ships it was last installed or upgraded. Those are the edits a cleanup would throw away.
• Referenced by an action — server actions, automated actions and activity types pointing at the template. That makes it in use even with zero recorded sends.
• Ready-made filters — Never Used, Used in the Last 90 Days, Not Used in 90+ Days, Customized, Standard, In Use, Unused and Unreferenced, Referenced by an Action, Shipped by a Module, Created in this Database, Enabled, Archived. Group by usage, model, source, module, language or last used.
• One query, whatever the size — the report is a single SQL view with grouped sub-selects, never a query per template.
• Read only — see the box below.
• Depends on mail only. No cron, no scheduled job, no outgoing traffic, nothing to configure.

Honest limitations. Counting starts at installation. Odoo stores nothing that ties an old email back to its template, so sends that happened before you install this module can never be counted — there is no history to recover. The First Used column tells you when tracking actually started to see each template. "Never used" is not a permission to delete. Templates are also called straight from Python code, from the Python part of server actions, and from configuration fields of other apps (stage-change emails, event registration, website and portal settings). Of those, only ir.actions.server and activity types are detected here. Always check a template before removing it — the report says so on every form. Send detection covers mail.template.send_mail() (and send_mail_batch() on 17.0+), and the Send Message / mass-mail composer when a template is selected in it. A module that renders a template by hand and builds its own email is not detected, and Odoo's Email Marketing app sends from its own mailing records rather than from mail.template, so those campaigns are outside this report. The counters live on the template row: delete a template and recreate it and its history starts again from zero. The Customized flag compares the template's write date with the install/upgrade date of the module that ships it, so upgrading that module re-applies its own version of the template and clears the flag again; a template created in this database is custom by definition. Access is restricted to the Settings group because the report exposes every template in the database. Its menu sits under Settings → Technical → Email, next to the templates themselves, and Odoo only shows the Technical menu in developer mode. On 14.0 and 15.0 the Enabled column is always ticked: mail.template only gained an active field in 16.0, so no template can be archived on those series.

Screenshots

Every email template on one line: the model it renders on, where it came from, whether it was customised, how many emails it produced and when it was last used. Red rows have no recorded use and nothing pointing at them.

Grouped by usage — used in the last 90 days, not used for 90+ days, never used — so you can see the shape of the problem before touching anything.

The shortlist to review: no recorded send, and no server action or activity type pointing at them. A starting point for a cleanup, not a delete list.

One template in detail — origin, customisation, usage, stored mails and references — with buttons to open the emails and messages it produced.

Installation

1. Copy the mail_template_usage_report folder into your addons path (or install it from the Apps store).
2. Open Apps, click Update Apps List, search for Email Template Usage Report and click Install.
3. No external Python library is required. The only dependency is mail, which every Odoo database already has.
4. Installation adds two columns (Source Email Template on mail.mail and mail.message) and creates the report view. Nothing else in your database is modified.

Configuration

1. There is nothing to configure — recording starts with the next email sent from a template.
2. Access is limited to the Settings group (Administration: Settings). Give that group to anyone who should be able to open the report.
3. Turn on developer mode (Settings → General Settings → Developer Tools) so that the Technical menu appears; the report lives under Settings → Technical → Email, next to Email Templates.
4. Leave it running for a while before drawing conclusions. A template used once a year looks unused for eleven months — the First Used column tells you how long the report has actually been watching.

Usage

1. Go to Settings → Technical → Email → Email Template Usage.
2. Read the list: Emails Produced and Last Used tell you what is alive, Source and Customized tell you what a module upgrade would overwrite, Referenced tells you what an automated action still needs.
3. Use Group By → Usage to split the templates into used recently, unused for 90+ days and never used.
4. Apply Unused and Unreferenced to get the shortlist of templates worth reviewing, and Customized to find the local edits that an upgrade of the shipping module would silently replace.
5. Open a line to see the full picture, and use Stored Emails / Stored Messages to read what the template actually produced.
6. Optional columns — language, module, first used, auto delete, archived, server actions, activity types, stored counts — are available from the column picker at the top right of the list.
7. Before deleting anything: check the template's name in your own customisations and in the settings of your other apps. This report cannot see a template referenced from Python code.

Version notes

The same features on every supported series (14.0 – 19.0). Two differences come from Odoo itself: mail.template has no active field before 16.0, so the Enabled column is always ticked on 14.0 and 15.0; and send_mail_batch() only exists from 17.0, so only that entry point is hooked on 17.0 and later.

License: LGPL-3 · Source on GitHub · Issues and contributions welcome.