I'm using FC5 and have the "nightly yum update" turned on. My FC5 box runs a mail server. Yesterday, there were no problems. Today, I can't send mail from PCs on the network... the Thunderbird client says "Connected to 10...." and eventuaally times out. >From external machines I can telnet to port 25 and it takes anywhere from 40-80 seconds to get a reply from the server. If I'm on the same machine as the server, the connection is immediate. That tells me it is not smtp that's slow, but something relating to external connections. I have not changed any configurations... but with the nightly updates, what could account for introducing such a delay? I'm thinking somethin like it's trying to a reverse dns look up to check the address connecting, and that's taking a long time? Any ideas/suggestions? Thank you, Don