My problem is that in some time magento doesn't send emails to customers ( order emails,invoice, registration confimation emails, etc ) . I have tweaked the magento code a little bit so that it would send automatically after a successful checkout of a customer but sometimes it doesn't send the emails, all email sending settings are enabled too in the system configuration. there's no logs for the emails not being sent, but if the emails were sent, the maillog is updated, now I'm really confused because I don't know what causes this error, and I really need to finish this up since the online store is now up and running.
If you're using Magento 1.9 version then you need to set CRON job on your server.
Hope it helps you
You will need to set up a cron job. Emails being sent out by Magento is always tricky with not all being sent. You might be best to use an email program like Mandrill who also have better success with spam filters.
It is key you get your emails going out for repeat business. It might pay to spend a little cash here.