Server :: Write A Cron Job To Delete Imap Processes Every Minute

I'm running my website on a linux server. I'm using a mac. Apparently, mac mail has a bug where it creates too many imap processes.

Since I'm on a shared server with a 25 process limit, with 3 email accts x 4+ processes each = a lot of problems!

I'm trying to write a cron job to delete imap processes every minute.

I've tried two things

1) following this blog's advice [URL]

Code:
killall imap

i realised it was imapd not imap, but i tried another method anyway

2) create a kill-imap.sh file in my server folder.

Code:
#!/bin/bash
/usr/bin/killall imapd

then executing the file from the cron command /kill-imap.sh

both these cases, it didn't seem to work!

I would get a daemon emai reply with

imapd: no process killed

just to give more info, the existing imap processes look like this

/usr/lib/courier-imap/bin/imapd /home/sitename/mail/sitename.com/emailusername

honestly, I'm not too experienced in this, and i've searched the net without luck. can anyone advise what i'm supposed to do to kill these imap processes every 5 min via cron job?