The owner has an iphone.
We have imapd - very simple setup.
His iphone is able to access.

But: He has a gabillion messages. He deletes NOTHING, and wants them all in his inbox. After X thousand messages, it gets odd. Subject header lists get out of synch, emails get "lost", only to re-appear.


But #2: we also experienced odd interaction with our android based imapd clients (both the default app and k9) when testing. So while it is not iphone specific, it seams to be phone client specific.

I organized his folder by year of message, which SEEMED to help, but it won't last. I need to address the real problem.

So:
#1 - What is the MOST number of messages that can be expected to be supported in the iphone's imap client interface? Who is this number provided by?

#2 - Once I have that I can then say: Ok, what do I need to do to make it bigger?