I avoided, delayed and ultimately never got to replying many emails in my life. I may have lost many opportunities because of this. The common cause for such an incident is lack of time or having other higher priority tasks at hand.
On the other hand, there are emails that you must always reply to. For example customer support emails. As a webmaster you have to handle many tasks. Repititive replies to emails can take a lot of time.
In either case, not replying to emails or replying to too many emails is all about time. I ran into an interesting software "Reply Email Automator" which looks like it could save time replying to emails.
The product is based on the model of creating standard templates of common responses. Then you can recall these standard templates within your email reader with shotrcut keys. The templates can also be triggered by keywords associated with each template.
You can store all your common customer inquiry responses or customer support feedback in a database provided by the software. The software can help you save time by automatically typing your signature line in your emails, message boards or chat rooms. It also has automatic web form filling functionality.
Imagine, if you have to reply to 10 emails everyday that takes 5 minute each, you are spending 50 minutes. With an automatic tool you could perhaps cut down each email response time to 30 seconds. That makes 5 minutes total for all 10 emails instead of 50 minutes.
I like products like this that save time. Saving time is equivalent to being more productive. Being more productive is getting more things done than you previously could. Getting more things done can increase your business profits and help you reach your goal faster.
You can read more details about the product at
http://computer-internet.marc8.com/ebook-info.php/name/reply_email_automator/toc_id/6-0-3-8/