What is the best practice to send an email to a large number of users?
I am developing a plugin for the website of an association and one of the things needed is to be able to send an email to all (or a specific subset) of the members of the association.
This will be a fairly rare thing to happen, but when it happens 500 to 1000 emails are expected to be sent.
Now, I can think of several options:
- Send each email separately
- Send email in blocks of 50/100
- Send one single email for everyone
Option 1 is nice because I can personalize the email (Dear Name Surname, ....), however we can live with a generic email for these situations.
- What are the drawbacks of each of those options?
- Can you advise any alternative strategy? I was going to simply use
wp_mailbut maybe relying on an external service (which one?) is better? I would like to avoid setting up a mailing list on an external server, I don't want to have two different databases with user info
- Is there a way to send the emails at regular intervals maybe using
wp_cron? How would you go about it?
Any further advice is very welcome.