This is where I would look first: 1. What is the value of the field reply-to" in the client's email preferences (it should be a valid email address)? 2. Has the server been updated with that information? 73, John On Wed, May 2, 2012 at 11:38 AM, Robert Krasowski <rkrasowski@xxxxxxxxx>wrote: > Interesting, he sent me today copy of error messages that he got from > PI4TUE. > Here we go : > > > "This is the mail system at host mailhost.tue.nl. > > > 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 > > > <sp8dxz@xxxxxxx>: host mx.poczta.onet.pl[213.180.147.146] said: 554 5.7.1 > > <sp8dxz@xxxxxxx>: Recipient address rejected: Spf check: fail (in > > reply to > > RCPT TO command)" > > > so from what I can say, spam filter rejected that email. is that correct?? > > Robert > KB2PNM >