sidekiq background job to send email and heroku worker

Question

Sorry for the basic question about Sidekiq's delaying ActionMailer. As per this article, Sidekiq can delay sending out emails by just saying UserMailer.delay_for(1.hour).....

Does this mean this is handled in the background now, or does it mean that it simply just delays sending the email out for an hour but once that hour comes, then the email is basically being sent like a regular ActionMailer, which slows down response time?

Or is it that if I truly want to do this in the background then I would have to do the other sidekiq stuff like putting it in a specific Worker and then firing it up that way?

Also, separately, if I do just do it via UserMailer.delay..., I presume I won't need a worker dyno on Heroku to save some money, correct?

Thanks for the help!

Answer 1

Yes, for emails you don't need to do anything else. It's like calling the Mailer 1 hour later. You just need to make sure you don't pass any complex objects into the mailer, for example a user object, you should only pass the user_id, because it will be stored in redis. On the Mailer fetch the user object with the given id.