I sent an invitation to join a meeting to a colleague. She did not receive the email, so I sent one (two or three, actually) to myself to check. I also did not get the invitation. I then copied the link to the meeting and pasted it into an email and sent it to her. She clicked the link, but got a page error.
Thanks for using Dimdim. Could you please let me know in which OS you have installed the conference server. If you have used the tar ball version of Dimdim, you need to configure the smtp server settings in dimdim.properties.
For Dimdim rpm package of linux, default smtp server settings are configured.
Please do let me know if this solves the problem.
Regarding the copy paste of the Join URL, were you able to join the meeting locally in your machine. What is the network setup you have?