Hi Derek, This diagnostic error code indicates a known Thunderbird issue sending mail when your time/date are wrong. Setup ntpd for best results. You also want to be sure you have perfectly acceptable PTR records for Yahoo and Gmail to enhance deliverability (although this has nothing to do with this problem): http://www.webmasterworld.com/apache/4231275.htm On Sat, Jul 7, 2012 at 9:03 PM, Derek Trotter wrote: > I don't know who else to ask, but yesterday and today I've had trouble > sending email to a friend who has a verizon.net address. Verizon keeps > rejecting them. Here's what I get back from them. I just don't know who > else to ask. Has anyone else had this trouble? > > thanks > > Message-id:<4FF90584.6030107@**gmail.com <4FF90584.6030107@gmail.com>> > Date: Sat, 07 Jul 2012 20:59:00 -0700 > From: Derek<######@gmail.com> > To: John<######@verizon.net> > Subject: just checking > > Your message cannot be delivered to the following recipients: > > Recipient address: @relay.verizon.yahoo.com:#####**#@verizon.net > Original address:######@verizon.net > Reason: SMTP transmission failure has occurred > Diagnostic code: smtp;554 Message not allowed - [320] > Remote system: dns;mx1-vzn.mail.yahoo.com (TCP|206.46.172.79|34174|67.195.168.231|25) > (mta1012.vzn.mail.ac4.yahoo.**com ESMTP YSmtp service ready) > > > ------------------------------**--------------------- > PLUG-discuss mailing list - PLUG-discuss@lists.plug.**phoenix.az.us > To subscribe, unsubscribe, or to change your mail settings: > http://lists.PLUG.phoenix.az.**us/mailman/listinfo/plug-**discuss > -- (503) 754-4452 Android (623) 239-3392 Skype (623) 688-3392 Google Voice ** it-clowns.com