registration email not being received by users

[laughingcrows]

First, thanks.  SMF is a great.

But I'm missing something.  It's not sending out the registration email using the default PHP mail.

I just did a fresh install of Mambo 4.6.2 - SMF 1.1.3 - SMF 1.1 Mambo 4.6 bridge 1.1

- I have Mambo and SMF sharing a database
- I'm wrapping SMF inside mambo
- SMF CSS = YES
- sync language = yes
- no mambo registration, I'm using SMF registration
- what else ...?  Oh yeah, I published all of the SMF mambots I had.

So go ahead and tell me I missed checking one box somewhere.

Thanks

(I searched, but couldn't find this resolved)