Best way to do email scheduling on a python web application?

I have a Pyramid web application that needs to send emails such as confirmation emails after registration, newsletters and so forth. I know how to send emails using smtplib in python and I decided on an smtp service (I think sendgrid will do the trick).

The real problem is the scheduling and delay sending of the emails - for example, when a user registers, the email is to be sent on the form post view. But, I don't want to block the request, and therefore would like to "schedule" the email in a non-blocking way.

Other than implementing this myself (probably with a DB and a worker), is t开发者_Go百科here an existing solution to email queue and scheduling?

Thanks!

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The existing solution to which you refer is to run your own SMTP server on the machine, bound only to localhost to prevent any other machines from connecting to it. Since you're the only one using it, submitting a message to it should be close to instantaneous, and the server will handle queuing, retries, etc. If you are running on a UNIX/Linux box, there's probably already such a server installed.

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In my app, I insert emails in DB table, and I have python script running under cron that checks this table and sends email updating record as sent.

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You can also use Redis Lists as a Queue to send emails. Create couple of worker processes which listens a Redis List, and

• publish a Email job via RPUSH or LPUSH
• receive the job at your worker via LPOP or RPOP

so that your web app worker process won't be affected, or not even feel the overhead for email sending operations.

This design allows you not to care how long does it take to send an email. The email service might be local or a external email service, however you want.