Registration Method

[softall]

I chose registration method, send email verification, and not send email 

[.m.]

forum admin panel >> configuration >> mail settings

which Mail Handler is used ? is Mail Logging set to log everything ?

forum admin panel >> tools & maintenance >> System Mail Log
do you see any logged entries ? if so, post a couple of the entries.

[softall]

Mail handler > PHP mail
Mail Logging > log everything

[.m.]

forum admin panel >> tools & maintenance >> System Mail Log
do you see any logged entries ? if so, post a couple of the entries.

[softall]

System Email Log
Error Message > MyBB was unable to send the email using the PHP mail() function.

[.m.]

contact your web host & ask to enable php mail. or if your web host provides smtp mail then you can try using it