G'day all, Some more info has surfaced that may help track down why list mail is bouncing off me ( see previous posts in thread www.redhat.com/archives/fedora-list/2007-October/msg03416.html ), but I'm still out of my depth. The list administrator sent a probe message which I forwarded to the ISP. This is what they said: Probe: This is the mail system at host vfep03.mfe.bur.connect.com.au. I'm sorry to have to inform you that your message could not be delivered to one or more recipients. It's attached below. For further assistance, please send mail to <postmaster> If you do so, please include this problem report. You can delete your own text from the attached returned message. The mail system <pyevet__aapt_net_au@xxxxxxxxxxxxxxxxxxxxxxxx>: host localhost[127.0.0.1] said: 442 Transaction failed; Message refused by BitDefender (in reply to end of DATA command) ISP: Thank you for your email. Upon further review of these email headers it is saying that you are blocking yourself. Local Host 127.0.0.1 is your pc, and bitdefender has blocked it, bitdefender being one of your security programs. It may need to be disabled or one of the settings adjusted to allow this email to be sent or received. : host localhost[127.0.0.1] said: 442 Transaction failed; Message refused by BitDefender (in reply to end of DATA command) Now as far as I know I'm not running bitdefender (ps aux | grep bit* shows nothing recognizable). The ISP has passed the IP addresses to the spam section to check they are not blocking anything. Thanks to everyone who advised me last year. I've been working on those workarounds (slowly). Still, I'm someone who always asks "Why is it so?" Does this extra info help identify where the block is? If it is me, how do I clear the blockage? -- Regards Simon