I needed a back-up account to keep all of my emails in. I created a gmail account, and started "bulk" forwarding messages from my ZD folders to this account. Each message I forwarded probably had 10-30 seperate email messages (forwarded a whole folder at a time) that were sent as attachments to the main message. The first few messages went just fine. On about the fourth or fifth, it quit sending and came up with a pop up box.
I cannot log into ZD now to re-create, so I will paraphrase as best as possible. I believe it said:
"Server appears to be busy. Try again later?" Then it had an "OK" box or a "cancel" box.
Now the ZD will not start (gets to the page where the plane, the plug and the road cycle back and forth, but then goes to a blank screen) I cannot see any new or old emails.