I verified the problem is exactly what was suggested, evidenced by detailed logging: 16:12:25 mail.MYISP.COM( 3) <<< MAIL FROM:<> BODY=8BITMIME SIZE=1156 16:12:26 mail.MYISP.COM( 3) >>> 501 bogus mail from Assuming I have no hope of convincing MYISP.COM of fixing this problem, is there any way to modify LISTSERV's behavior so that it does not use an empty MAIL FROM string? I'm not sure why it is doing it in the first place, and why L-Soft defends its use. Why doesn't it just put listserv's address in there? Is this problem perhaps fixed in 1.8e, which I have not yet installed? -- Dave