The defendant set up a false account under the name “Pizarro’s mother”, in reference to the mother of the mayor she repeatedly insulted for the past few months.
The woman, from the south-eastern Spanish town of Plasencia, sent out insulting tweets to other local politicians, their relatives and other people with links to Spain’s ruling Popular Party.
“It’s in particularly bad taste,” Plasencia mayor Fernando Pizarro told Spanish daily 20 minutos with regard to the defendant’s Twitter name.
In Spain, any insult that makes any reference to somebody's mother is considered especially rude.
"I wasn't looking for any financial remuneration from this person but I did want her to stop the personal insults."
Pizarro and the woman had reached a verbal agreement prior to the case; the judge deciding to follow on from this arrangement and handing the woman a minor fine but ensuring she sent out a public apology on Twitter.
If she does so, she will not have to close her account.
The murder of Spanish politician Isabel Carrasco last May turned Twitter into a hotbed of debate in which some users justified the crime as a comeuppance.
Spain’s ruling PP ordered police to monitor the social media site to crack down on offensive content, spurring critics to point out the lack of freedom of speech under the country’s right wing government.
The issue of Twitter abuse also made national headlines recently when Spanish police arrested 17 people, including two minors, accused of promoting terrorism and humiliating terror victims online.