#60 Too many simultaneous connections


To avoid a problem already highlighted (some mailboxes
remain stuck in a 'connection to host...' status), I
suggest to avoid to open a connection for every single
mailbox to check: the new TCP/IP implementation in XP
SP2 limits the number of connections a single thread is
granted to a very low limit (I reckon 4) to limit the effect
of a SMTP virus engine running. Opening 'n'
simultaneous connections for 'n' mailboxes to check
when the program starts, or every 10 minutes (it's the
default) may 'hang' many mailboxes on a 'connectiong
to host...' status, because the TCP/IP stack refuses to
open a connection.
If the mailboxes are stored into an array, I suggest
to 'sweep' the array at the program start, one mailbox
after the other.
And to avoid to open more than 4 simultaneous
connections when is't 'polling time'.
A temporary suggestion to avoid this 'congestion' is to
set each mailbox with a different polling time, using
prime numbers (the most important mailbox with a
polling time of 2, then the less relevant with a timing of
3, the next at 5, then 7, 11, 13, 17, 19, 23, 29...). This
reduces significantly the possibility of multiple
simultaneous connections. (tested, with 35
mailboxes...) (Don't ask me why I've 35 mailboxes, it's
my job!).
My mailbox is corrado.mella@blueyonder.co.uk


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