Most email providers have this option on their web mail site. It is best done there.

How do you go into web mail?

Depends on who your provider is. Mine is Comcast and I go to Comcast.net

Thank you, mine is Comcast as well. I'll try that.

https://support.mozilla.org/en-US/kb/Vacation-Response

Actually none of these responses helped. I actually figured it out by goo-gling the question and found my answer on:

http://forums.mozillazine.org/viewtopic.php?p=2362453

I followed the steps it said to do and it works. Unfortunately one week to late though, I'm already back from Vacation. It will help for next trip.

Thank you everyone for your help.

Well Debbiemc that is all well and good, as long as your computer is turned on, Thunderbird is running and there are no glitches with your power or internet that require it to be reset for the entire time you are absent.

So we no not recommend or even suggest it as a practical solution to the problem. The practical solution to the problem is to use the away or holiday service offered by almost all web mail systems. If you can not find the setting contact your mail provider and ask them where it is.

Thank you Matt, but it works for us. We keep our computers on with thunderbird running and should something happen with the power or internet that require it to be reset, no worries. But I will look into the other solution as well.

Thank you for your input.