[Dovecot] Maximum number of connections from user+IP exceeded

[Ben]

> IDLE is not required for this.  Polling, which is the default on all
> MUAs,

Not entirely sure I'd call it "the default", Thunderbird seems to setup 
for IDLE as default these days, and I suspect Apple Mail and any of the 
other popular ones do too.

The source code probably looks something like
if (canIdle) then
	{do stuff}
else
	{do polling}