Is there a log file size limit?

[Damien Hull]

I've been trying to figure out why /var/log/mail.log rotates when it 
wants to. It should be once a week but it happens mid week. Someone told 
me to look for a size limit in a config file. I couldn't find one. 
However, /var/log/mail.log seems to rotate at about 1.1 megabytes. It 
also rotates once a week. That's why things looked strange. I had a 
small file after the weekly rotation and then a large one at 1.1 megabytes.

There must be a config file somewhere that sets the size limit on log 
files. Can someone tell me where this is or where I should look?