I have been swamped for the last two months, working all day, every day, until extremely late into the night (or morning, depending on how you look at it), and at one point I found myself without time to do basic things like taking a quick look at the (snail) mail.
When it came to email, I would take a quick look, respond to those messages that appeared urgent and/or critical, and then move on, back to my projects. I had a variety of phone calls during that time, and found myself doing the same thing - responding promptly to clients, and telling myself that friends would understand if they didn't hear back from me for a while.
It was not a good feeling. Nor was being "swamped" a good excuse.
We all have a lot on our plates, don't know which end is up, coming, or going, are crazy-busy, or just don't see a light at the end of the tunnel. It may be a matter of work overload, lack of organization, poor planning, a fondness for drama, or an inability to say "No!" The reason is for you to figure out and act on; I would like to address the effects your actions, or lack of action, has on others.
Respond to phone calls within 24 hours.
There are all sorts of reasons someone may contact you and often times you won't know until you call back. It may be something quick and easy, or you may need to say "I would love to talk but I'm in the middle of some things; can we plan a time for a phone call in a week or so?" Schedule the call on your calendar, much like you would a client meeting or doctor's appointment. It may not be ideal, but at least you will have connected.
Answer emails quickly.
Email messages come in all sizes, length and depth. Some may only need a fast answer, while others can take research, thoughtful wording, and follow-up calls before they can be considered "taken care of". For those that do not require immediate action, I try to reply and let the sender know I will be in touch by ______. This way, the person knows I received the message and it is on my to-do list, and I know that someone is not waiting and wondering why I haven't responded in any way.
Personally, seeing an inbox piled high with multiple messages adds unneeded stress to my life, so at the end of the day I take five to ten minutes to go through the list and sort everything that is left into appropriate files, knowing where the files fall on my priority list. I may still have a lot to do, but this way, I feel like I have some control over it, rather than the other way around.