After letting the logs run verbose for a while this morning, it initially appears to be a problem with a specific server (MX3.hotmail.com). Any mail sent to that server is getting the 554 Transaction Failed error. However, any mail being delivered MX1, MX2, MX4 appears to be delivered successfully. Can any one else confirm this? Thanks. John Traweek Senior Account Director Publishing Concepts, LP 12840 Hillcrest Rd, Ste 230 Dallas, TX 75230 Phone - 972.774.3280 Fax - 972.774.3284