How can I configure Thunderbird to allow me to use any of the chosen accounts to send my email. This is something which is very helpful for me in MS Outlook.

Use case:
I use different SMTP accounts to send email addresses. Also they serve me as backup when tbere is any problem in my main smtp account.

Also in Outlook when I reply to an email it automatically uses the reply to be routed through the same account from which it came. Can I have that facility in Thunderbird?


How can I have multiple accounts setup yet disable some of them for synchronization?

Use case:
When in office I have a mercury server which gets all the emails from different accounts for me. So I just connet to a single account. However when on road that server is not accessible. So I directly connect to the different pop accounts from my email client to fetch the emails. Normally such accounts are present in my outlook client, yet disabled. However on the road I enable them and disable my corporate intranet email server. How can I do this in Thunderbird?

I also posted these questions in the support forum. Please go to http://forums.mozillazine.org/viewtopic.php?t=190801
to view responses, if any, from the forum members.