i dont use email clients much myself, but if u want one, try sticking with clients like incredimail or bat or eudora or thunderbird.
dont put ur trusts on M2, security is a biiig issue and M2 sux bigtime in this matter. the other day, i configured M2 in opera 8 to access my fastmail account, and it downloaded a trojan from a spam mail! i was lucky kaspersky detected and deleted it. so according to me, M2 is a big no-no.
btw, if u want a text based email client, ie, which only shows text in the email (no images or multimedia content), use ePrompter. this way, u'll know if u have new mails and dont have to worry abt attachments either.