php mail() not working and TLS error

    Hello.


    Verison of i-MSCP: 1.3.0


    I have installed few Wordpress for customers on my server, and all plugins like "Contact Form 7" use php mail() function to send the mail from the server.


    The mail will go to the emails that are hosted on the server but on outgoing emails like @gmail.com @hotmail.com etc no one will receive any emails that they should get.


    So I tried to send an email from my personal address from this server to an email address @gmail.com and that work fine, I can send and receive emails trough Roundcube/Rainloop/Thunderbird.


    So I tried also to install Wordpress SMTP mail sender, and filled out the information for the server to login/ports and etc and I send "Test Mail" on my mail address and I was tailing log for mail while using the SMTP plugin.


    I get this:


    SSL_accept error from subdomain.domain.local[127.0.0.1]: 0
    Sep 11 21:49:15 subdomain postfix/smtpd[13344]: warning: TLS library problem: error:14094418:SSL routines:SSL3_READ_BYTES:tlsv1 alert unknown ca:s3_pkt.c:1300:SSL alert number 48:
    Sep 11 21:49:15 subdomain postfix/smtpd[13344]: lost connection after STARTTLS from subdomain.domain.local[127.0.0.1]
    Sep 11 21:49:15 subdomain postfix/smtpd[13344]: disconnect from subdomain.domain.local[127.0.0.1]


    And about the php mail() I do not have any clue about what is wrong there cause I am not getting anything in logs.

    For your first problem (php mail() mails not being accepted): Can you give us any logs that state, that these mails are bounced? Most big providers have some quite strict spam filters.


    To solve your new problem, you could try disabling TLS and connecting to localhost. That shouldn't be a security problem as this is just a local connection.

    Hello, thanks for your reply.


    About the php mail() error log I do not get any logs about, and I am tail mail.log and also syslog but no errors are there about that php mail().


    About the TLS error, I am using WP mail sender where I can choose "No encryption" "SSL connection" and "TLS encription" I have chosen "No encryption" so the plugin should not be using TLS connection.