Peter McCann, of Pinfold Road, Bushey, was arrested in Watford on November 5 after attempting to incite a child into sexual activity.
He was jailed for three years and nine months on Monday (June 19) when he appeared at St Albans Crown Court.
Volunteer group Innocent Voices had carried out a sting after another team sent them an evidence file with messages he had exchanged with an adult “decoy”.
He was then detained by the group and arrested by Hertfordshire police, in Park Avenue, Bushey.
McCann pleaded guilty to engaging in sexual communication with a child and attempting to incite a child into sexual activity on December 19, 2022.
He was also sentenced over making indecent photographs/pseudo-photographs of a child for an overall sentence of 45 months imprisonment.
A sexual harm prevention order was made and he was added to the sex offenders register, both indefinitely.