I believe I just had this happen yesterday as well but can't confirm it. There was no mail loop that I can find. Do you know if there is a way to track down if a client was trying to submit a message that is larger than the message size limit?
-----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: Thursday, December 16, 2004 4:06 PM To: Exchange Discussions Subject: Entourage and Out of Control Transaction Logs A serious issue with Entourage 2004 as an Exchange client has come to light in our environment. About two weeks ago our Exchange 2003 (SP1) server dismounted all of its databases because it had run out of transaction log sequence numbers. We went through the workaround described in article 830408 (http://support.microsoft.com/default.aspx?scid=kb;en-us;830408), and were able to get the server running within three hours. Over the next couple of days we opened a case with Microsoft and began investigating the circumstances surrounding our problem. We were generating transaction logs at the rate of about one thousand per hour. Given the available sequence numbers, we would run out again within forty-five days. After eliminating message loops and antivirus software as the possible causes of the high rate of transactions, our engineer turned to Entourage. Microsoft had recently dealt with a similar case: http://blogs.msdn.com/jeremyk/archive/2004/11/11/255705.aspx To summarize that case, they found that when an Entourage user attempts to send a message that is larger than permitted in the Exchange environment (Exchange System Manager -- Golbal Settings -- Message Delivery properties -- Defaults tab), the message gets stuck in the Entourage Outbox. Entourage is unable to handle the error returned by the Exchange server. The client then attempts to send the message again, repeating this cycle ad infinitum. To determine whether Entourage was the culprit, we decided to block Entourage clients from communicating with the message stores. The quickest way to prevent Entourage 2004 from talking to the server is to stop the World Wide Web Publishing service. We needed a bit of lead time to notify our one hundred Entourage users that they'd be without email for half an hour, so we scheduled the outage for the next afternoon. In the mean time, we did decided to remove all internal message size restrictions, per the advice in the blog entry above. The next morning, our log file creation rate had dropped to about two hundred per hour. Later that afternoon we stopped the w3svc for twenty minutes, and our log production rate was cut almost in half -- forty-four logs produced in the twenty minutes preceding the outage; twenty-four logs produced during the Entourage outage. Even when it's not encountering an error while trying to send a message larger than allowed, Entourage generates an unacceptably large amount of transactions. At the current rate, our remaining sequence numbers will be consumed within six months, so we're not out of the woods yet. Also, we've reinstated a "receive" limit of ten megabytes to prevent large messages from filling up a recipients mailbox. As there is not a "send" limit, this appears to prevent the problem described in the blog entry. The Entourage and/or Exchange product teams are supposedly working on a fix for this problem. Whether it will only address Entourage's inability to handle a message size error, or whether it will also address the unacceptably high "chattiness" of the client remains to be seen. More details: Exchange Server 2003 Enterprise Edition SP1 600 Mailboxes across 4 message stores in one storage group 100 Entourage 2004 clients 500 Outlook (PC and Mac) clients Began migration of Mac Outlook users to Entourage in mid-July Transactions per second prior to removing message size limits in Exchange: Average 94; Max 537 Transactions per second after removing message size limit: Average 50 Transactions per second after stopping w3svc: Average 30 Log file production rate dropped from 1000 per hour to 72 per hour when Entourage couldn't talk to the server. Go figure. _________________________________________________________________ List posting FAQ: http://www.swinc.com/resource/exch_faq.htm Web Interface: http://intm-dl.sparklist.com/read/?forum=exchange To subscribe: http://e-newsletters.internet.com/discussionlists.html/ To unsubscribe send a blank email to [EMAIL PROTECTED] Exchange List admin: [EMAIL PROTECTED] To unsubscribe via postal mail, please contact us at: Jupitermedia Corp. Attn: Discussion List Management 475 Park Avenue South New York, NY 10016 Please include the email address which you have been contacted with. _________________________________________________________________ List posting FAQ: http://www.swinc.com/resource/exch_faq.htm Web Interface: http://intm-dl.sparklist.com/read/?forum=exchange To subscribe: http://e-newsletters.internet.com/discussionlists.html/ To unsubscribe send a blank email to [EMAIL PROTECTED] Exchange List admin: [EMAIL PROTECTED] To unsubscribe via postal mail, please contact us at: Jupitermedia Corp. Attn: Discussion List Management 475 Park Avenue South New York, NY 10016 Please include the email address which you have been contacted with.
