I would like to keep my maillog for one month before rotating it.

I did add monthly on the /etc/logrotate.d/syslog file but it has not effect.
Currently the maillog file is rotated every Sunday.

I do not wish to change the default for all other logs which is defaulted to weekly in the /etc/logrotate.conf file.

Any suggestions and help will be greatly appreciated.

We will probably need to see your logrotate configuration file...

My three files
/etc/cron.daily/logrotate
/etc/logrotate.conf
/etc/logrotate.d/syslog

Take a look at maillog - I have added "monthly" to it.
Another way around it is to remark it out and do it manually.
But I think it can be done using logrotate.

/etc/cron.daily/logrotate
********************************************
#!/bin/sh
/usr/sbin/logrotate /etc/logrotate.conf

/etc/logrotate.conf
*****************************************
# rotate log files weekly:
weekly

# keep 4 weeks worth of backlogs:
rotate 4

# create new (empty) log files after rotating old ones:
create

# uncomment this if you want your log files compressed:
#compress

# some packages install log rotation information in this directory:
include /etc/logrotate.d

# Rotate /var/log/wtmp:
/var/log/wtmp {
monthly
create 0664 root root
rotate 1
}


/etc/logrotate.d/syslog
****************************************************
/var/log/cron {
postrotate
/bin/kill -HUP `cat /var/run/syslogd.pid 2>/dev/null` 2>/dev/null || true
endscript
}

/var/log/debug {
postrotate
/bin/kill -HUP `cat /var/run/syslogd.pid 2>/dev/null` 2>/dev/null || true
endscript
}

/var/log/maillog {
monthly
postrotate
/bin/kill -HUP `cat /var/run/syslogd.pid 2> /dev/null` 2> /dev/null || true
endscript
}

/var/log/messages {
postrotate
/bin/kill -HUP `cat /var/run/syslogd.pid 2> /dev/null` 2> /dev/null || true
endscript
}

/var/log/secure {
postrotate
/bin/kill -HUP `cat /var/run/syslogd.pid 2> /dev/null` 2> /dev/null || true
endscript
}

/var/log/spooler {
postrotate
/bin/kill -HUP `cat /var/run/syslogd.pid 2> /dev/null` 2> /dev/null || true
endscript
}

/var/log/syslog {
postrotate
/bin/kill -HUP `cat /var/run/syslogd.pid 2> /dev/null` 2> /dev/null || true
endscript
}

I am having the same issue, did you find an answer? I would like to rotate certain log files daily and then keep them for 30 days but I don't want the system log files rotated daily, just too much mess :P

add 'monthly' in /etc/logrotate.d/syslog file