Summary files always being rebuilt

I am not sure what you mean by "inbox", I have nothing in the Inbox folder itself, but I do have lots of subfolders under the Inbox folder, some of which do have more than a 1000 emails. I also have lots of other folders on the same level as the Inbox folder, some of those with subfolders, and many of which have large numbers of emails stored for future reference. In this day and age of giga byte and tera byte drives I should think a mail client should not really care how many emails a user wished to store.

For me, it is an extremely time consuming process to try and manage so much, all the time, and delete those which I don't need. I do go through them about once a year when I have a spare day or two, but most of the time I cannot be bothered to sort through and delete unnecessary email. If that is a requirement for using TBird, then that may break it's usability for many of it's users! (I, for example, subscribe to a LOT of mail lists, some of which I manage/moderate, which is why some of my folders can get rather large. That is why I need to keep email in a handy archive. I often have to retrieve old email and use TBird's search capabilities a LOT!)

I do not understand why you are implying that there is a connection between large email folders and having to rebuild summary files before new email can be seen/read. Please explain your thinking on this, and I hope it is more that just saying TBird is flakey. To me, this rebuilding of summary files has to be triggered by some difference Portable TBird is seeing when it is executed under different computers. My first guess is perhaps it is looking at and comparing time stamps or file path differences somewhere... Keep in mind this is happening even when I move from one Linux/Wine system to another, or from one Windoz system to another, as well as from one OS to a different OS..... File path differences might be the trigger because my USB drive gets mounted at different mount points and that seems highly likely to be the trigger for making it necessary to rebuild summary files. (Especially since a rebuild of summary files is not triggered because of a reboot of the system that my USB drive is connected to. File paths are not likely to change then.)

If Portable TBird is looking at time stamp differences, to trigger a summary file rebuild, that seems to be a very dangerous choice to be using in a PortableApps environment. To be comparing file path differences seems unlikely, but symptoms are pointing in that direction, and again in a portable environment that would be a poor choice to be using to trigger summary file rebuilds. I would have thought file size differences would be the likely trigger, but I am seeing summary file rebuilds occurring on folders/mail stores where NO changes occurred. Got me beat, I dunno what other file attributes TBird would care about and monitor in order to cause it to trigger a summary file rebuild...

I use a POP account and do not have the choice of using IMAP at the moment.