The trick is, don't download or upload email, from or to, your computer.
Use an external source like Yahoo, Gmail etc..
If you want to write an email, do it off-line, in Notepad or Wordpad,
bring up the Yahoo, etc.. go in and setup as to compose an email message then
do a copy from notepad and paste to the composition.
In that way before you decide to send, you can edit it before going on-line.
Only open your mail on the server leaving any virus's there. They can have them, you don't want them.
If you need a copy of any mail, when reading your mail on-line, you can highlight,
do a right-click and copy, open your notepad and paste. There, you've got your mail with no virus's.