Send Later

[Development and maintenance of this add-on is supported by Extended Thunder Inc., a non-profit organization dedicated to supporting free, open-source Thunderbird add-ons. Please support Extended Thunder to help ensure that add-ons like this one continue to be available. You can make a recurring donation at LiberaPay or a one-time donation at PayPal. Donations to Extended Thunder are tax-deductible in the United States as permitted by law. Thank you!]

This add-on changes the “Send Later” command (Ctrl+Shift+Return) in the message composition window, so that instead of merely copying the message into your Outbox so that it is sent the next time you go online or do “Send Unsent Messages”, a dialog pops up which allows you to specify when the message will be sent.

You can specify a specific time and date, or click “15 mins later”, “30 mins later” or “2 hours later”, or define custom shortcuts. You can also schedule a message to send repeatedly using simple rules (every N hours, days, etc.) or customizable functions.

User guide | Questions and Feedback | Bug reports

Send Later relies on powerful date input parsing provided by Andrew Plummer's Sugar.js library.

Please get in touch about bug reports and suggestions!

Improvements

Send Later now obeys the `mail.sanitize_date_header` Thunderbird preference. If this preference is set to true then, as with messages sent directly without Send Later, the `Date` header inserted into scheduled messages upon delivery will be in the UTC timezone and will always have `00` for the number of seconds.

There is a new `autoUpdateDraftsFolders` advanced preference which defaults to false. If you set it to true then whenever Send Later iterates through all Drafts folders it will tell Thunderbird to refresh them. You may need this if you schedule messages on one machine and have another machine deliver them; you probably won't need it otherwise. If you do enable this, you should configure Thunderbird to synchronize your Drafts folder locally because otherwise the performance impact could be noticeable, especially if you have a lot of drafts.

Bug fixes

Many people reported that the Send Later scheduling window was disappearing immediately after it popped up when they clicked on the Send Later button in a compose window. This appears to be due to a bug in Thunderbird. As a workaround, the scheduling window has been modified so that it is no longer "attached" to the button and is instead a separate window which does not exhibit this problem.

We have continued to see consistency issues when editing scheduled drafts and rescheduling them, e.g., the changed content or schedule not being saved to the IMAP server, old versions of the draft continuing to appear in the Drafts folder, etc. These issues have been observed most frequently with Gmail but may also occur with other types of mail server. Two changes in Send Later have been introduced in this release to attempt to mitigate these issues:

Each time a draft is saved it is assigned a new messages ID (this was the behavior of the add-on before it was inadvertently removed by the previous maintainer).
We now compact the Drafts folder each time we save a scheduled draft.

[This is a copy of our official privacy policy. While we make every effort to keep this copy in sync, if you would like to see the "canonical" version you should look there.]

Send Later collects anonymous usage data to help us improve the add-on, measure its usage, and identify where to focus our efforts. The data we collect contains no identifying information, email content, or account information. We don't share the data with anyone.

What we collect

We collect the following data:

the version of the add-on you are using;
the name of the application Send Later is running in, e.g., Thunderbird;
the version of the application Send Later is running in;
your operating system and hardware platform;
the locale (i.e., language and region) configured in your operating system; and
events and errors that occur within the add-on (but just to to be clear, identifying information and content are carefully excluded).

We also collect by default a persistent, unique identifier so that we can associate disparate data points with the same Thunderbird user. We cannot associate this identifier with any individual since we do not collect any personally identifiable information. If you wish, you may disable the collection of this identifier as described below while still allowing other data collection.

When we say we don't collect any identifying information, we mean it; our data collection server (which we host and control) does not even log your IP address. Furthermore, when we say we don't collect the data, we mean that it isn't even transmitted to our data collection server, i.e., we are careful to ensure that the add-on only transmits the data that is appropriate to collect.

For those who are so inclined, you can search our source code to see exactly what data we are currently collecting.

How to opt out in or out of data collection

If you have not opted in or out of data collection before, then you are initially opted in, and the add-on prompts you on startup to ask whether you wish to allow data collection. Click the Yes or No button on the dialog to respond.

If you would like to change your answer, open the add-on preferences, expand the Advanced configuration editor section, find the line in it with the key telemetryEnabled, change its value to either "true" or "false" as desired, and click Save.

If you would like to opt in or out of a unique identifier being associated with your data, open the add-on preferences, expand the Advanced configuration editor section, find the line in it with the key telemetryUUIDEnabled, change its value to either "true or "false" as desired, and click Save.

Right to access your data and right to be forgotten

If you have opted out of data collection then we have no data about you whatsoever for you to access or for us to be able to delete.

If you have opted in to data collection but opted out of a unique identifier being associated with your data, then it is impossible for us to tell you what data we have about you or delete it, since there is nothing in the data associating it with you in any way.

If you have opted in to data collection with a unique identifier and you would like to know what data we have about your usage of the add-on, please contact us with your request. Include in your request the value of the telemetryUUID preference in the Advanced configuration editor in the add-on preferences. We will either send back an export of your data or remove it from our database as requested. Note that if you do not disable data collection as described above, the add-on will continue to collect new data about you even after we've deleted the old data upon request.

Some add-ons ask for permission to perform certain functions (example: a tab management add-on will ask permission to access your browser’s tab system).

Since you’re in control of your Thunderbird, the choice to grant or deny these requests is yours. Accepting permissions does not inherently compromise your browser’s performance or security, but in some rare cases risk may be involved.

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Send Later 10.4.0

by Jonathan Kamens, Jonathan Perry-Houts

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About this Add-on

Developer’s Comments

Version Information

Version 10.4.0 Released March 31, 2024 624.9 KiB Works with Thunderbird 102.0 - 126.*