I started a thread about this issue on SmarterMail support forums, but did not get much attention. My thread is here:
http://forums.smartertools.com/forums/thread/28169.aspxI have my own SM instalation and this issue prevents me from switching many users from POP to IMAP, as they are using Thunderbird and I'm not able to copy their messages to the server (I mean directly - yes, I can either transfer their messages and folders through other mail server to SmarterMail or use KMail on Linux to import messages and folders from Thunderbird and then copy them to SmarterMail, but that's both rather complicated).
I tried many clients and it seems this problem have all mail clients based on Netscape, but only in connection with SmarterMail - I tested Netscape 7.2, Thunderbird (versions 1.5, 2 and 3 alpha) on Windows and on Linux and Seamonkey. Copying to SmarterMail works in Outlook, OE, WindowsMail, KMail and others.
Also I found out that the problem probably seems to have some relation with the speed of copying - when I'm copying messages from local folder to the IMAP folder, I'm not able to copy more than four messages, but when I'm copying messages from one IMAP account to another (which is slower), it can copy up to 19 messages before it says the connection has been lost.
And, by the way, I have SmarterMail 4.2 beta now and the problem is still the same.
If you at CrystalTech found any solution, please update this thread to let us know.
** UPDATE ** JLance from SmarterTools found a source of this problem, the description can be found here:
http://forums.smartertools.com/forums/permalink/32233/32218/ShowThread.aspx#32218They will add a workaround to this in 4.2.