How to slow down outbox sending rate in Thunderbird?

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I want to send 1,000 emails to 1,000 address using Thunderbird. The emails are generated using a Windows MAPI.

When these mails and rendered, it will send immediately. Rendering 1,000 mails takes less than 1 minute and it will send to ISP’s SMTP server immediately. The SMTP server will treat this as spamming activity.

If I may slow down the sending rate to about 50 mails a minute, then these emails will all get through.

I couldn’t find any option or add-on in Thunderbird to limit the sending rate? Do you have any ideas?

Chau Chee Yang

Posted 2015-03-01T05:03:34.980

Reputation: 802

Why are you attempting to send 1,000 e-mails from your own system? That is definitely considered non-normal usage from an ISP standpoint. – JakeGould – 2015-03-01T05:06:44.210

Do you mean 1,000 messages to each of 1,000 recipients? 1E6?? If not, you might use a mail merge add-on, such as https://addons.mozilla.org/en-US/thunderbird/addon/mail-merge/, with perhaps 50 CSV files, called by a script with delay.

– DrMoishe Pippik – 2015-03-01T05:20:08.607

I may delay calling MAPI in Windows application. But if Thunderbird has a similar function, then I may just render emails in Thunderbird's Outbox and let it send mails in background. – Chau Chee Yang – 2015-03-01T05:43:46.007

There is the 'Send Later' add-on for Thunderbird but this won't help you I think. See some discussion at https://support.mozilla.org/en-US/questions/995418. Much the easiest solution I think is for you to build in a delay in your application.

– gogoud – 2015-03-01T06:51:05.080

I shall use "Sleep" or "Delay" to slow down sending rate. – Chau Chee Yang – 2015-03-07T03:45:39.803

Answers

2

The combination of two plugins solves this problem.

You need Mail Merge plugin to send a certain number of emails periodically to your Outbox, and then use BlunderDelay plugin to send unsent messages in the outbox in a specific period of time.

In your case, you should set Mail Merge options like the following picture: (Pause=2)

Mail Merge Image

Also set the sending period in BlunderDelay option to "Every 1 minute":

BlunderDelay Image

Then, 30 emails are sent every 1 minute.

Masood

Posted 2015-03-01T05:03:34.980

Reputation: 21

BlunderDelay add-on is not compatible with Thunderbird v68.2.1 (64-bit) – Arya – 2019-12-08T03:53:24.653

Asked: 2015-03-01T05:03:34.980

Viewed: 3 769 times

Active: 2018-05-24T13:37:00.463