Sending newsletters in bulk

I have a newsletter — Venetian Stories about the history of Venice — with a couple of hundred recipients.

For some time, I have managed that with a free WordPress plugin. One of those with a PRO version, and every update shifted some functionality over to the paid version.

When I wanted to move the newsletter from my History Walks Venice site to a dedicated domain, there was no way of migrating the plugin data without moving to the PRO version. Several functions I had used for a long time, were no only available for payment.

Confronted with these futile complications, I decided to return to basics.

The newsletters would be sent from my mail application of choice, as HTML emails, with all the recipients in the BCC field.

I have my own mail server running Mail-in-a-box, so all outgoing email would originate from that server.

Sending a single email to two hundred recipients, of which about half are on Gmail, could easily see my mail server throttled or even blocked, which is a very real problem when you have your own mail server.

To avoid this, I had to throttle outgoing mail from my server, so they’re delivered a bit at a time.

My mail server runs Postfix, and all I needed to do, was add these few lines to the /etc/postfix/main.cf configuration file:

smtp_destination_rate_delay=60s
default_destination_recipient_limit = 2
smtp_destination_recipient_limit = 2

This will limit the server to two mails each minute for each destination mail server.

These parameters are probably very conservative. Delivering a hundred emails to Google’s servers will take fifty minutes, but better that than being blocked by one of the big guys.