imap_checkinterval in mutt 1.3.15i

[Pedro Zorzenon Neto]

Hi,

   I upgraded from mutt 1.2.5i to mutt 1.3.15i.
   The old version had the variable imap_checkinterval, but the new one doesn't work 
with it.
   Which is the config var that can be used for setting the imap check interval?
   Or where can I find a variables list for 1.3.15i?

     Thanks in advance
     Pedro