I use an email client software to download all emails so that I can view it offline and reply later when I am free. When the emails are downloaded to the computer, they are saved locally on the hard drive. As I get more emails, the database size is increased and possibly slowing down the email software. When this happens, I am only left with two choices which is either to delete some of the really old emails that I don’t think is important anymore or use a new database without any emails and start afresh. I have more than 10,000 emails on my email client software and it would probably take days or even weeks to go through all of the messages so using a new database would be a better solution.
First I save or move the old database to another location and when I want need to search for some old emails, I can use Mail Viewer to directly view messages from the email database.
Mail Viewer is a free and portable tool that can load email database created by Outlook Express, Windows Mail, Windows Live Mail and Mozilla Thunderbird and then shows the messages just like an email client, except that this is an on-demand tool that is only used to read email messages without changing anything on the database. Running Mail Viewer will ask you to choose the email database that you want to open. You can either click on the folder icon to browse the email database or click the Browse current store button to load email database that is current on your computer.

After selecting a valid email database, you then get to choose identity or folder that you want to view. To view the email message, simply double click on the line and a new tab will open displaying the subject, sender, recipient, CC, BCC, size, timestamp, plain and HTML view, and even attachments. There is also a source tab where you can view the email headers.

Mail Viewer has a powerful filter and search capability so that you can look for the email that you want to find. First select the filter from the drop down list to choose where you want to search and then type the keyword at the search box. A tip to jump to the next tab is by using the shortcut key Ctrl+Tab. In fact Mail Viewer can even open multiple email databases at the same time. Another interesting feature is Mail Viewer can automatically collect email addresses from the database by clicking the Messages > Collect e-mail addresses. All the email addresses and names will be captured and displayed at the bottom of the window.
Mail Viewer supports 9 languages (Cestina, German, English, Spanish, French, Italian, Polish, Portuguese – Brazilian and Simplified Chinese). Mail Viewer is free to use for both private and commercial users and runs from Windows 95 to Windows 7.