Does any one have the contact details for gemxwave ?

[Ian McVicar <icm63@xxxxxxxxxxx>]

Hi, 

I have tried emailing the guy of Gemxwave at Gemxwave@xxxxxxx, but I get no
response.I guess this is his email distribution tool.

Question : What is the best software to distribute emails to a large
distribution list, say 500 emails at one time ?

Thanks in advance.

Ian