If I understand things correctly, e-mail can be easily intercepted via a packet sniffer on you SMTP traffic. If that is the case then what is the best way to secure you e-mail?

Although it's easy to use a packet sniffer to read email traffic, it's not so easy to get a packet sniffer into a place where it can be used to do that. The system administrators at your ISP could do it, but I couldn't.

You can check whether your ISP supports SMTP AUTH/TLS and if they do you can use the howto at http://www.linuxquestions.org/linux/...MTP_AUTH_Howto to configure your mail setup. I used it here and only had to change a couple of things for my system. My ISP doesn't use encryption, but my wireless clients here do.

You could also use PKI technology to encrypt your mail before it leaves your PC. Have a look at PGP or GPG (http://www.gnupg.org/) and EnigMail (http://enigmail.mozdev.org/) if you use Thunderbird/Mozilla.

Currently some of my client use MS exchange and outlook. I would like to change the e-mail server to linux and keep the outlook clients. Is this feasable and how would I go about doing this? many thanks

//Moderator note: you have crossposted a message, which is against the LQ Rules. Cross-posting is considered bad netiquette on your part, a waste of resources on LQ's part and a waste of time for LQ members who take the time to read and answer your question.
Please do not do that again.
*Besides that this aint no Linux - Security question so it would have been pruned RSN anyway.

FUP to: http://www.linuxquestions.org/questi...d.php?t=426815