This is a problem I've run into over the years, and it grows more prevalent as I venture forth into the Publishing industry. Many of the email contacts I have for writers are secondary "free" email addresses, ones that the authors in question may or may not check on a regular basis.
I'm often left wondering if my emails are getting through when I send something to certain people and they never reply. When I fail to get any kind of response to my messages, I can't tell if they've failed to get the letter, or they are just ignoring me. It's entirely possible that some people have no interest in talking to me, or giving me the courtesy of saying "no thanks" to a particular invitation, but it's also a great concern that they may be missing out on something because they've changed email addresses, or forgotten about a certain inbox they set up way back for special purposes.
I'm sorry to say I've also lost a few email addresses over the past year, including some belonging to distant cousins I was talking to about our shared ancestry. If you haven't heard from me recently, feel free to drop me an email, and let me know how you're doing. I've still go the same earthlink email, if you're wondering (I'd particularly like to hear from a certain Counts cousin whose email was lost in my last computer crash last year). Note to self: In future, keep a written record of email addresses in case of disaster!
The moral of today's blog post: check your email, and please respond if you get something from me, even if it's to say "stop writing me, you freak!" It'll help everyone involved.