Notifications email not being read because of domain change

So we changed from cleverdodo.mu and cleverdodo.co.uk to cleverdodo.com. Previous users had whitelisted our .mu/.co.uk email address during the registration process and that allowed future emails from the site to be delivered directly to their inbox. With the move to .com, our emails are more likely being dumped into their spam/junk folder. So any notifications for new comments are not being read.

I could potentially send emails through the .mu/.co.uk depending on which site the user registered but at some point we're going to have to ditch those domains and use the .com version as that's going to be the main site going forward.

Shall we count our losses and keep moving?