MyBB Community Forums

Hello,
I have chosen the SMTP mail handler option in Mybb ACP config. When a new user registers or loses his password, an email is sent both to confirm the registration or to reset the user password.
However when someone sends a message to the forums admins, through the contact page (contact.php which is the default one that comes with mybb), no emails are sent to the contact email (which is different from the email from which all forum messages are sent: for example, [email protected] is the email from which the messages from forums are sent and my contact email is [email protected]).
Plus, when a user subscribes a thread (or more) by email, he does not get any emails of new posts and updated.
Therefore I don't know what to do. Can anyone help me? 

Thank you,
Pmx.pt

admin panel >> tools & maintenance >> System Mail Log
does it have any entries ? if it does then post the recent entry

(2016-02-20, 03:20 PM).m. Wrote: [ -> ]admin panel >> tools & maintenance >> System Mail Log
does it have any entries ? if it does then post the recent entry

It does not have any entries related to thread subscription by email nor related to contact page.
More details:
My administration email (sender email): [email protected] (this is an example)
My return email: [email protected] (this is an example)
Contact email: [email protected] (this is an example)
Thank you,
Pmx.pt

^ have you also tried php mail ? and have you contacted your web host to check smtp mail ?

(2016-02-20, 06:19 PM).m. Wrote: [ -> ]^ have you also tried php mail ? and have you contacted your web host to check smtp mail ?

I have tried to use php mail yes but in that case it doesnt send any email at all (maybe it is because I do not know how to make php mail work in an ubuntu server. I have currently postfix and dovecot installed but I dont know how I make php mail to work). 
Yes I have contacted my host (vps host) and they said they do not block anything so I assume SMTP mail is enabled. Otherwise activation messages would not be sent to users awaiting activation.
If you think php mail is the best option than could you brief me on how to setup it in an ubuntu server? I would be glad 
Thank you,
Pmx.pt