sometimes antivirus scanning emails might corrupt the email header, which becomes inaccessible to use.

How would the previous sentence be correctly capitalized?
Answer: Sometimes antivirus scanning emails might corrupt the email header, which becomes inaccessible to use.
the light blue color.

How would the previous sentence be correctly capitalized?
Answer: The light blue color.
he had already published a major work on control of systems contrôle optimal de systèmes gouvernés par des équations aux dérivées partielles in 1968 which investigates deterministic optimisation problems involving partial differential equations.

How would the previous sentence be correctly capitalized?
Answer: He had already published a major work on control of systems Contrôle optimal de systèmes gouvernés par des équations aux dérivées partielles in 1968 which investigates deterministic optimisation problems involving partial differential equations.
help diego clean the streets with his tractor

How would the previous sentence be correctly capitalized?
Answer: Help Diego clean the streets with his tractor