About 5 days ago I suddenly started getting an error when trying to send "Shipping Notifications".
Error read: "The SMTP server requires a secure connection or the client was not authenticated. Server response was 5.5.1 authentication required . . . . . ."
I had not upgraded SixBit in about 6 months but subsequently upgraded to version 3.00.208 and had same issue. Nothing at all changed on my computer running Windows 7. Never had this problem before and have been running SixBit for several years.
Any suggestions on what may have suddenly changed and how to fix?