Long time since I wrote something. I had a spamming story left half way through. Let me get to the meat of it right away…
The first step in the analysis was ascertaining the volume of e-mails still in queue. I must say Qmail is really good in handling the mail queue effectively(when compared to exim).
This article explains how to migrate email accounts/mailboxes from a sendmail server to a Qmail server. A challenging task for any sysadmin implementing a Migration would be to migrate all the email accounts from one Mail server to another preserving all the settings, such as usernames and passwords.
This document helps you, only if your Qmail system is installed with VpopMail (not VmailMgr). Installing and configuring qmail+vpopmail is out of the scope of this article.(Refer to qmailrocks.org and lifewithqmail.org to install Qmail and Vpopmail) This article exclusively covers only the Migration aspects.
Here is what you have.
* Sendmail server, the list of usernames, the corresponding system passwords (encrypted, not clearpasswords) and the Mailboxes
* Qmail server with VpopMail.