"A customer of ours notified us this afternoon that they have been receiving the same email from us over and over again. At least 10 times (maybe double or triple that by now) requesting that they pay for their order. We can't see these as outgoing emails through eBay to this customer so we think maybe something is happening with SixBit. Can you please check on this?"
Upgrade to the latest full version of SixBit. Then, run through the following checklist:
1. Make sure your machines running SixBit are on the current version of SixBit
2. Machines not sharing a networked database should have email automation turned off to avoid duplicate emails being sent by the network database (Open the File/Application Menu (the File button or little orange guy in the top left corner of SixBit) | Database | Open Database to see what database SixBit is connected to)
3. On machines that do connect to a shared database, make sure only the server is running the SixBit Agent