I installed a Typesetter 5 - Cms and the Cms automatic filled for php mail() in:
AutomatedSender@mydomain.000webhostapp.com
and the email is send but no testmail arrives at my emailaccount.
(the choice of sendmail instead PHP mail() gives an error)
Since this cms has no problems at other providers it may be the automated sender etc. Who knows how the exact address is ?
Tried parking a domain against your account?
No - i do not have a domain - its just a free site - the php-info says that the sendmail directory is there but the sendmail function is not(empty field behind)
php mail should function - hopefully - if i need a domain why is there a switch for mail in the general settings ?
If you’ve got the option to use SMTP try that, else if you’ve got to rely on phpmail then try using a real email address you own so you can get any bounce reports, and check the spam of the accounts you are sending to + give it a few hours to see if anything turns up 
In the CMS i have the SMTP-Option, but if the system is cracked (just because of a security hole) then the hackers have the passwords and can do things before a notice it.
My server is Linux 63339.us-imm-node4a.000webhost.io
I fear that the phpmail-port is diabled because the CMS says that the mail was sent. Either sendmail or php-mail should function - but there is no way to contact the support for an answer - and to order a domain will probably not help.