Fourteen staff are to be sacked from the Driver and Vehicle Licensing Agency (DVLA) in Swansea over pornographic e-mails.
The DVLA said pornography was downloaded from the internet
The action comes after a three-month inquiry by the centre, which handles the UK's driver and vehicle records.
The 14 sacked sent pornography outside the DVLA. Another 101 were disciplined for sending "inappropriate material."
A spokesperson said: "DVLA has started dismissal proceedings against 14 members of staff for gross misconduct."
According to the DVLA, pornography was downloaded from the internet by staff before the images were attached to e-mails sent around the building, in Morriston, Swansea.
Managers began an investigation and IT experts pinpointed which of the DVLA's 6,000 staff were using the machines involved at the time.
The DVLA said 14 staff will be dismissed.
The others were disciplined for sending "inappropriate material" but not pornography and received various degrees of reprimand, including final warnings.
The spokesperson added: "The staff concerned were found to have used the agency's electronic systems to send pornographic e-mail attachments out of the agency, in direct contravention of DVLA's code of conduct."
In a separate incident last year, a woman working at the DVLA was suspended over claims that mobile phone clips of her having sex were seen by hundreds of colleagues.
One of south Wales' biggest employers, the DVLA processes driving licences for the UK.