My blog got its all time high number of visits on 3rd May. It registered more than 4000 visits. This post is not about bragging about my blog. The heavy traffic translated into a small issue. A few popular posts were getting lots of traffic and comments. In fact, I got about 300 comments on that day. I had email notifications for comments turned on. I also have the Subscribe to Comments plugin installed to enable users to subscribe to followup comments.
WordPress uses a function called wp_mail to send emails. I had got about 42 subscribers to comments on a particular posts. Thus every time a comment was posted, about 43 emails were sent by the wp_mail function. There was a particular time when too many comments were posted in a short span of time and the script started using too many server resources. Thus my host, Godaddy killed the process. Thus, WordPress was unable to send any emails like comment notifications and contact form mails.
I tried disabling and re-enabling comment emails and plugins that use the wp_mail function but nothing seemed to work. I searched for solution to this problem everywhere but found no help. 24 hours later, I started receiving emails again. Godaddy automatically re-enabled the script after 24 hours.
One thing I've learnt the hard way is that I need to keep a check on email subscriptions whenever I get heavy traffic. I've been looking for alternatives to using the wp_mail function. I tried a couple of plugins-WP-Mail_SMTP and Climy Swift SMTP to try to use my SMTP server in place of the wp_mail function but they don't seem to work for me. For now, I've decided to disable comment subscriptions temporarily during heavy traffic period.
This also explains why I haven't been replying to all the comments. I've been busy with all this for the past two days. I would like to apologize to all my readers who didn't get follow-up comment emails or whose comments I didn't reply to.