With the yahoo plugin:
If you have more than some number of messages (say, 30;
I don't know the exact number) and you download them
within a certain timeslot (say, 10 minutes), I do
observe the behavior someone else reported. I get the
remainder of the messages beyond the unknown cap that
have no subject, no body, no to/from, but simply blank,
and date/time of the email is the same time as the
error occurrence date/time.
The event logger has a bunch of red-background message
saying "This should not happen".
Now, at the same time, if you attempt to log into yahoo
webmail with a browser, it gives a "999 This page is
currently unavailable" error message warning as the
page name, and this text is shown in the browser:
This page is currently unavailable
Unfortunately, we are unable to process your request at
this time. We apologize for the inconvenience. Please
try again later.
The algorithm must be time-based. I.e., no more than X
messages in Y minutes because I have been able to
dowload 50 messages at one time. However, if I
download two or three batches of 25 messages a couple
of minutes apart, the account is temporarily blocked
for about 15-30 minutes.
So, as a workaround, I suggest perhaps if there is a
way to modify mrpostman to only download X messages
every Y minutes?
I was told by yahoo support to try and login with
another machine with another IP address, so perhaps
they are limiting the number of accesses per minute.
The ironic thing about this is that I read somewhere
that this even happens for paid accounts.