krileon wrote: Just schedule 2 CRON tasks 1 after the other.

Thank you, I was able to figure a better way to achieve this. Please let me know if for any reason this is not optimal or shouldn't be done.

since both crons are running every 30minutes i've added priority by using the "nice" cron command as follows:
expiration cron = nice -10 cronurl
mailer cron = nice -5 cronurl

this should place the expiration with top priority and allow it to be executed first.