Forgot password and notification emails

[francoisdb]

A forum member has forgotten his password to log in to my forum. But now I get an email from this person that he does not receive a confirmation email to create a new password answer. The person also checked his spam box to see if he had not arrived there. Also, no more notification emails are sent.
Forum version is 2.1.4

[Kindred]

1- is that person using Gmail?
2- Is your forum sending ANY emails?
3- are you using phpmail or SMTP?