New profile verification email not sent

Hello,
I am new to Indico. I have set up Indico at https://viettesol.org . Everything seems to run perfectly but when a new profile is created, no verification email was sent out although reminder emails were sent.

How can I fix this?

I found this topic but it seems no effective solution is provided: Verification emails are not been sent when users signup

SOLVED. The SMPT credentials were not correct. Apologies for bothering but I hope this is a useful lesson: you might have done something wrong so reviewing your steps carefully first.