I m getting strange messages from your calendar app which i deleted and it countiniusly sending me messages about some virus and porn sites that i dont use so please resolve a problem becouse it is disturbing

If running iOS 13 or earlier versions, check: Settings - Passwords & Accounts - Accounts - Any rogue entries here? If so, delete the rogue account. 

If running iOS 14 or higher, check: Settings - Calendar - Accounts - Any rogue entries here? If so, delete the rogue account. 

The Apple support article is below. 

Remove calendar spam

Video support

Hi,

Sorry to hear you are having issues with spam Calendar events.

The following resources should be able to help resolve your issue:

• Delete spam calendars
• Report a junk calendar event invitation on iCloud.com
• Mail - Official Apple Support
• Use iCloud calendar subscriptions

Hope this helps.