I've sent an invitation to someone to join Dropbox, but they haven't received my email. Any ideas?

[Who_am_I]

I invited someone to join dropbox by adding their email. But they have not received the email. I double checked the email and it is correct.

I wanted to invite so we could both receive more space.

Can some help ?

thanks

[Who_am_I]

understood.  Thanks for letting me know that there is a cap on referral totalling to 16GB.