bbs.spamgourmet.com

In the registration for Cisco's online learning, one is required to provide an email address.

The registration 'works' with a spamgourmet address.

However, Cisco do other checks subsequently over a period of several days, and Do Not Accept spamgourmet email addresses, regarding them as throwaway accounts, which are 'not allowed'.

Whether or not you believe Cisco are incorrect in their characterisation of spamgourmet accounts as 'throwaway accounts', the practical effect is that you should not use spamgourmet email addresses to register for Cisco online training.

Which is a shame.

Perhaps you could try using the primary domain name of 0sg.net or ob.0sg.net. I've found that a lot of sites are checking the domain name and rejecting it if is an alias. All the other domains (spamgourmet.com, dfgh.net, etc.) are aliased to the primary name.