SINGAPORE - Unhappy and angry with the service he had received from a woman at a telco, he e-mailed her, her colleagues and senior management obscene content with sexually explicit material to tarnish her reputation.

One of the messages contained nine attached images of nude women engaging in sexual acts with animals, and identified the 48-year-old victim and the organisation she was working for. But none of the images were that of the victim.

On Wednesday (Oct 12), the perpetrator, David Daniel Liu Fu Long, 39, was sentenced to 13 weeks' jail after admitting to two charges each of transmitting obscene objects and intentionally causing harassment to another victim, a 44-year-old female doctor.

In the first case, Liu sent e-mails to the 48-year-old victim and her colleagues with obscene objects at about 1am and 8.15am on Aug 6, 2016, said Deputy Public Prosecutor Samuel Koh.

Liu admitted that he had sent the e-mails as he was unhappy and angry with the victim's service, and intended to tarnish her reputation.

The 1.04am e-mail showed nine purported images of the victim naked, and added that she could be seen "naked several times a day in her house".

Although the image attachments were labelled using the victim's name, none were actually of her. She experienced great distress and embarrassment as a result of this.

She lodged a police report the same day. Four days later, she e-mailed the relevant investigation officers, saying that on Aug 9, she had again received an e-mail containing obscene objects with gruesome and intimidating material, which had also been circulated.

Investigations showed that on Aug 9, Liu sent an e-mail to the victim containing two attached images of dead cats run over by vehicles on a road.

The e-mail also claimed that one of the cats might have to enter hell as retribution and punishment for its bad deeds, and that the victim should be quarantined for sharing the same name as the cat.

As a result, the victim felt extremely disturbed and intimidated, as she interpreted the e-mail as a death threat.

Liu told investigators that he sent the e-mail to the victim and others as he was dissatisfied that he had not received any reply following previous e-mails he had sent.

In the other case, the court heard that Liu created an e-mail address on July 26, 2015 to impersonate a 44-year-old female doctor to send an e-mail to her colleagues. In the e-mail, he described the doctor as a prostitute, a gang member, an Institute of Mental Health patient, and that she should resign and be imprisoned.

DPP Koh said the case was quite aggravated, malicious and vindictive. What made it worse in this case was that Liu was targeting the victim within her workplace, which had a serious risk of endangering her livelihood.

Liu has two previous convictions.