[quote user="bfluet"]
Two things to check.
1. Make sure there is not a max message size set. The setting is in the Download controls tab of the POP3 host configuration.
My setting is "0", which I presume means that there is no max size. (The meaning of "0" is not covered in "Help".)
2. Check the timeout settings. There is one in the General tab of the Internet Mail options and one in the General tab of the POP3 host configuration. The host configuration takes precedence but if it is set to zero the other one is used as the default. More info in the help file. I set mine at 120.
Aren't those two actually the SAME setting? If I change one, the other is automatically changed as well. I changed mine to 120, but I doubt that that is the problem.
[/quote]
I analyzed the session log clips I posted previously a little more. I noticed something that I did not address last time, and there's the possibility that it points to Pegasus Mail as the culprit.
On the SUCCESSFUL downloads, Pegasus waited 0.266 secs, 0.281 secs, 0.282 secs, and 0.359 secs for the ISP server response.
On the UNSUCCESSFUL downloads, it appears that Pegasus waited 0.000 secs for all four responses--that is, it didn't wait at all!
I don't know why Pegasus would behave this way for downloads greater than some (arbitrary??) size.
I don't know of any setting anywhere in Pegasus for indicating the minimum length of time that Pegasus must wait for a server response. (For example, in my case, it might be useful to specify that Pegasus must wait at least 0.5 sec (or 1 sec, or perhaps even more) for a response from the ISP server before it gives up (as it seems to do now on an instant basis). Does such a setting already exist? If so, where is it located, so that I can change it?
Thanks to all who can provide further help or information!
Harvey