I wrote earlier about the obvious need to let customers and clients know that you are going to be away on vacation. The flip side of this professional consideration is to let people know when you get back and catch up with messages, e-mails, requests and orders as soon as you possibly can.
If a simple e-mail works to let people know that you will be gone, you can send a simple e-mail letting people know that you have returned. Many people like to set their e-mail preferences to send out a message letting people know that they are gone and telling them when the plan to be pack. I still think it is a good idea to make personal contact with individual clients and customers and let them know you are back on the job—unless you have too many to reasonably contact or your business is so impersonal that it doesn’t really matter.
As for catching up, return e-mails and voice messages as soon as possible. I try to give myself about 2 days to return e-mails and phone calls and 5 days to get caught up. This keeps me from feeling too much stress and allows me to prioritize and decide what needs to be tended to first in order to catch up, and still have time to devote to doing ordinary tasks and not falling farther behind.
I think it is perfectly all right to tell your customers and clients that you have just returned from vacation or a trip and that you will not be able to tend to their request for a day or two. You can contact them and tell them something like: “I am just getting back from vacation and I am working through all of my messages. I will try to get back with you by Wednesday, but if you do not hear from me by then, please feel free to contact me.” You have let them know that you are back, working through things, and that you are taking their request seriously—plus giving yourself a deadline for getting back with them.