Forum How many emails to members can I safely send out?
 

I recently changed the domain of my forum and want to send an email out to members informing them of the changes to the site.

However, there are 43,000 members on the forum. Is it safe to use vbulletin's built-in mail functionality to email all of my members, or is that likely to get my server IP blacklisted? If the latter is true, what are my options to avoid it?