Richard Hayes, 40, sent 16 letters containing the powder to the offices and home addresses of MPs, MEPs and local councillors over a three-year period.
Exeter Crown Court heard one politician went to hospital after opening a package and the accident and emergency ward was put into "lockdown" while the powder was analysed.
Staff were quarantined in constituency offices on other occasions, with police in protective suits called in to deal with packages sent by Hayes.
One local councillor who received one of his letters decided not to stand for re-election to protect herself and her young children.
The white powder inside each of the packages was found to be a harmless mix of flour, protein powder and bicarbonate of soda.
Hayes committed the offences between 2011 and 2014 but was not caught until 2018, when he was cautioned for harassing a former partner.
His DNA matched samples takes from the lick strips and stamps on the envelope, with his handwriting also similar to the addresses written on the front.
Mrs Justice May jailed Hayes for five years, highlighting how he had targeted women in public office.
"Over a three-year period, you posted envelopes containing a white powder to politicians including MPs, MEPs and local councillors," the judge told Hayes.
"All of them were women. I have read all of the statements setting out the distress and disruption caused by your actions.
"In each case, the powder turned out to be inert but none of your victims, nor the postal service, or the emergency services attending had any way of knowing this."
The judge accepted that Hayes did not have "political motivations" when he committed the offences.
Rachel Drake, prosecuting, said "extensive investigations" took place into who was sending the hoax letters but Hayes was not identified until last year.
He was cautioned for harassing his former partner by sending her pizza and taxis, with police taking his DNA and fingerprints.
Hayes was arrested by counter-terrorism officers on July 18 and later admitted 16 charges of making a noxious substance hoax, contrary to Section 114 of the Anti-Terrorism, Crime and Security Act 2001.
Charges state that he did so "intending to induce in a person anywhere in the world a belief that it was likely to be or to contain a noxious substance ... thereby endangering human life or to create serious risk to human health".
His first letter was sent to the Liberal Democrat constituency office of Welsh assembly member Kirsty Williams in April 2011.
Police were called and put the office in "lockdown" for two hours, leaving one member of staff and her three young children terrified inside, Ms Drake said.
Later that year, Lib Dem councillor Lianne Williams in Manchester and Heidi Alexander, then-Labour MP for Lewisham East, received letters from Hayes.
Margaret Thompson, a Lib Dem councillor in Hook, Chessington, was taken to hospital in June 2011 after opening a letter and white powder inside caused her eyes and skin to itch.
"She was taken by ambulance to hospital which was put into lockdown," Ms Drake said.
Baroness Sarah Ludford, then-Liberal Democrat MEP for London and Helen Jones, Labour MP for Warrington North, also received letters from Hayes.
He targeted local councillors in Exeter, sending packages to Yolanda Henson, Vanessa Newcombe, Rosie Denham and Catherine Dawson.
Mrs Dawson said: "The incident deterred me from standing a second term as councillor."
In October 2012, Hayes sent a package to Emma Reynolds, Labour MP for Wolverhampton North East, and Nicola Blackwood, then-Conservative MP for Oxford West and Abingdon.
The following August, Hayes sent a package to Jessica Lee, then-Conservative MP for Erewash, and Chloe Smith, Conservative MP for Norwich North.
In April 2014, Hayes sent a package to Rebecca Harris, Conservative MP for Castle Point in Essex.
Hayes, who has no previous convictions, told police after his arrest that he held "no grudge" against any of the women he sent letters to, Ms Drake said.
Representing Hayes, Emily Cook described her client as a "gentle individual" who wished to apologise to those affected by his actions.
"This was someone who bore them personally no ill will and never intended to physically hurt them," she said.
Hayes, who has a mild developmental disorder, committed the offences after the breakdown of a relationship with a female partner.
He was inspired by a case in Wales in 2002, when Welsh First Minister Rhodri Morgan was sent hoax anthrax mail, the court heard.
Detective Chief Inspector Ian Butler, from Eastern Region Special Operations Unit (ERSOU) Counter-Terrorism Policing unit, described Hayes' actions as "sick and senseless".
"The effect of the hoaxes orchestrated by Hayes in today's society is far reaching, as it triggered understandable panic and emotional distress to those involved and their families," he said.
"This distress is unlikely to ever leave the victims, some of whom have described life-changing consequences in the years since the attacks."