On Mon, Mar 09, 2015 at 02:10:16PM -0400, James B. Byrne wrote: > <x...@cuttingedgegrowersupply.com>: host mx01.1and1.com[74.208.5.21] > refused to talk to me: 501 Syntax error in parameters or arguments
Perhaps they don't like your EHLO name. $ posttls-finger -o myhostname=shorthelotest "[mx01.1and1.com]" posttls-finger: Connected to mx01.1and1.com[74.208.5.21]:25 posttls-finger: < 220 perfora.net (mxeueus003) Nemesis ESMTP Service ready posttls-finger: > EHLO shorthelotest posttls-finger: < 501 Syntax error in parameters or arguments posttls-finger: EHLO rejected: 501 Syntax error in parameters or arguments > We are getting these rejects when attempting to send to addresses at > this domain and only this domain (so far). Can someone provide some > insight as to what might be happening here? How can it be fixed? report the output of: $ printf "---%s---\n" "$(postconf -h myhostname)" $ printf "---%s---\n" "$(postconf -h smtp_helo_name)" Make that "-hx" instead of "-h" if your Postfix is recent enough. -- Viktor.