Richard Heggs, systems analyst at the council, said it desperately needed to update its e-mail server as the previous proprietary system was proving unreliable.
The system crashed six or seven times a day, messages were being lost and some messages were being sent several times. "As we have to concentrate on delivering electronic government services, this was unacceptable," he said.
Ten months ago, Heggs invited Suse Linux to put together a specification for a more scalable e-mail server. At the time, Suse advised against using its own Suse Linux E-mail Server III product, as it would be unable to cope with the large numbers of users.
After 17 days of consultation costing £17,000, Suse specified an alternative e-mail system based on open source components. The system runs on two servers, a 4-way Xeon server with 4Gbytes of Ram and a two-way Xeon machine with 2Gbytes of Ram. Heggs recently replaced the internal disc storage on the e-mail server with a storage area network.
Taking into account the time and effort involved in implementing and configuring the system, together with the Suse consulting fee, Heggs estimates the total cost to date to be about £60,000, equating to just £8 per end-user mailbox over a year.
By comparison, Heggs said he was aware of another local authority with 5,000 users where the overall software and hardware bill was £1m a year.
According to Ashim Pal, vice-president at analyst firm Meta Group, the cost of running commercial systems such as Microsoft Exchange and Lotus Domino can be more than £80 per user per year, but these products have features open source systems lack.
At Nottingham City Council, users connect to e-mail either via a web user interface or from Outlook on Windows PCs. Heggs made some changes to the source code as a result of user feedback, but said he was now happy with the reliability of the server and said it had improved dramatically.
In the past, concerns have been raised over the long-term viability of open source, but Heggs was confident his system could be supported because he had access to the source code. "We have a great deal more flexibility when it comes to support options and we are not compelled to rely on one supplier," he said.