Well... it sounds it there is a break in recognized authentication. Are these clients working offline or cached? Local network? VPN'd? What AV/client-firewall is in place?
On Mon, Jun 23, 2008 at 2:28 PM, ExchList <[EMAIL PROTECTED]> wrote: > Mike: the domain is MY domain. This has happened while sending to multiple > external domains [possible 5 or 6] (two of which perform zero filtering). The > funny thing is that when employee #1 was sending to external_Recipient_XYZ > and getting it bounced, Employee #2 was able to successfully send to > external-Recipient_XYZ. Then several hours later employee #1 can successfully > send mail to the same recipient again. > > Joseph Danielsen, CSBS, MCSA-2003, MCSA-2000 (Messaging), MCP > Network Blade Inc. > 49 Marcy Street > Somerset, NJ 08873 > 732-213-0600 > www.networkblade.com > > Ask me why a Microsoft Certified Small Business Specialist is best for your > company > > > > -----Original Message----- > From: Micheal Espinola Jr [mailto:[EMAIL PROTECTED] > Posted At: Monday, June 23, 2008 1:45 PM > Posted To: Exchange > Conversation: Mail Server Requires Authentication Bounce Message > Subject: Re: Mail Server Requires Authentication Bounce Message > > mail.domain.com #5.5.0 smtp;503 > > Is mail.domain.com your domain or the final-recipient domain? How > many external domains does this problem occur with. Is it always the > same ones? > > > On Mon, Jun 23, 2008 at 11:19 AM, ExchList <[EMAIL PROTECTED]> wrote: >> Oh my gosh am I about to hang myself over this problem; with what seems to >> be a simple issue is evading me for a solution. >> >> Exchange 2003 SP2, Windows 2003 R2 (patched) >> >> >> >> A few times per week, users will report that when sending to 'one >> particular' email address - it gets bounced with the message below. Other >> outbound messages from the client at that time will go through. And at the >> same time if another employee sends an email to the same recipient it will >> go through. Each employee that experiences this bounce message is sending >> to a different recipient/domain; and they don't always get bounced. >> >> >> >> My research has revealed a number of old posts with the same problem but do >> not provide any solutions. >> >> >> >> I case of beer for the one who solves this for me - so I can sleep at night. >> PLEASE HELP ME! >> >> >> >> mail.domain.com #5.5.0 smtp;503 This mail server requires authentication >> when attempting to send to a non-local e-mail address. Please check your >> mail client settings or contact your administrator to verify that the domain >> or address is defined for this server. >> >> >> >> Joseph Danielsen, CSBS, MCSA-2003, MCSA-2000, MCP >> >> Network Blade Inc. >> >> 49 Marcy Street >> >> Somerset, NJ 08873 >> >> 732-213-0600 >> >> www.networkblade.com >> >> >> >> > > > > > -- > ME2 > > ~ Ninja Email Security with Cloudmark Spam Engine Gets Image Spam ~ > ~ http://www.sunbeltsoftware.com/Ninja ~ > > ~ Ninja Email Security with Cloudmark Spam Engine Gets Image Spam ~ > ~ http://www.sunbeltsoftware.com/Ninja ~ > -- ME2 ~ Ninja Email Security with Cloudmark Spam Engine Gets Image Spam ~ ~ http://www.sunbeltsoftware.com/Ninja ~