I am using DT3 3.9.2 on macOS 12.6.8.
In the past I have archived my emails into to different groups. I do not remember why I did so. Now I want to merge all those emails in only one group. Therefore I want to move appr. 56.000 emails into the other group. The other group contains at the moment appr. 700 archived emails.
The green arrow shows, what I want to do:
Can I move these emails without loss or trouble?
Of course. And as it’s in the same database, this should be also a quick operation.
For what it is worth, I have done this a huge amount lately, and my personal experience is that it is far faster to do this by selecting the messages to move and using the context menu for “Move To” than by, say, trying to click and drag tens of thousands of messages between groups.
Clicking and dragging is fine for a small number of messages, but does not scale well to the multiples of thousands.
Agree with the others but exporting the DB-Archive as a Backup beforehand (see here) is always a good idea for non-standard operations on many files at the same time.