If you are using Sendmail or Postfix only internally (i.e., you receive no mail from the Internet or you pull it off of POP/IMAP servers with fetchmail and then dump it into the mail system), no there are not major security issues. IF, you trust all users. If you are receiving mail directly from the Internet (i.e., a MX record for some domain points to your IP address), a hole has to be made in the firewall for SMTP (port 25) access and yes it does make a difference. HTH, Jeffrey Quoting Brian Durant :

Hi again,

I am using a LinkSys router/firewall for my LAN, in connection with a cable modem. SuSE 7.3 Pro is at this time, simply running on my desktop as part of a dual boot (Win 2k) system and not serving anything to my LAN. I believe that inbound connections are blocked via the NAT (by the router), so is there any real security differences between using Sendmail or Postfix? Should I implement the SuSE personal firewall for added protection with Sendmail or is this irrelevant? Ideas? Advice?