At last i have decided to shift the servers. The previous downtime & database errors made enough damage. The old server was hosting more than 600 websites in the same ip. This increased overhead and high CPU load causes the slow response.

The new server is super fast & we have a 99.99% SLA. TechTalkz.com & TechTalkz Blog successfully migrated to the new host. Still the mail service remain unresolved. I am trying my best to make it up soon.

Thank you very much for your co-operation.