Issue in email notifications

Hi Team,

We are using webissues 1.1 from last 2-3 years.
Now we want to enable email notification for any activity on any task (immediate notification)
We have configured custom SMTP server and test mail is coming to our email I'd. Also configured manage alert on my task folders. But I am not getting any email.

Our cron is running for more than 2 hours and not finishing properly.
It's getting timeout after 2 hours.
How to resolve this issue. Can we increase cron timeout?