reading encrypted e-mail packets

cisco linksys wireless g broadband wifi

sounds like a home environment, right?

now i want to read captured e-mails.

That depends how you are accessing the mail server. As these days most of these connections to mail servers are encrypted (HTTPS, IMAPS, etc.) your chances to bee able to read e-mails with Wireshark are pretty bad, unless you own the mail server and are able to get the server RSA key. This is usually impossible with servers like gmail.com, yahoo.com or any other online mail servers and it's rather complicated (up to impossible) to get the key from a company mail server (like Exchange) unless you are the mail server admin.

If you read your mails through unencrypted channels (POP3, IMAP, HTTP), you would be able to see that in Wireshark, but then I would strongly recommend to switch to encryption, because others would be able to read your e-mail as well!

So, how do you read your mails?

Regards
Kurt