programming chelahmy

msmtp  requires a minimal setup for sending emails via SMTP compared to sendmail. Here is a configuration for you to send emails from a web host to an external SMTP server. Prior to doing that, you must check whether there is a clear communication channel between your web host and the SMTP server. You can use Telnet . Set up msmtp You are going to set msmtp as an MTA . Hence, you need to remove all other MTAs such as postfix and sendmail: $ sudo apt-get --purge autoremove postfix sendmail Install msmtp and related utilities: $ sudo apt-get install msmtp msmtp-mta mailutils Configure msmtp: $ sudo nano /etc/msmtprc # Set default values for all following accounts. defaults # Use the mail submission port 587 instead of the SMTP port 25. port 587 # Always use TLS. tls on # Set a list of trusted CAs for TLS. The default is to use system settings, but # you can select your own file. tls_trust_file /etc/ssl/certs/ca-certificates.crt # The SMTP server account mx host mail.mx.example

You want your webhost to be able to send emails through an external SMTP server. The first thing to do is to check whether your webhost provider allows this to happen. Some concerned providers block outgoing SMTP ports to prevent you from doing email spamming. Let's try to connect with the SMTP server via Telnet from within your webhost. You may need to SSH into your webhost first. And then issue the following command: $ telnet -4 mail.example.com 587 The above command will connect to the mail.example.com SMTP server via port 587 and force Telnet to use IPv4. If the connection fails then your webhost provider may have blocked the outgoing SMTP port 587. You may need to politely ask your webhost provider to open the port for you. You can't do it yourself. Note: Telnet will resolve to IPv6 by default. If the SMTP port is not open on IPv6 then Telnet will appear hung until all trials via IPv6 connections are timed out. If IPv6 failed then it will resolve to IPv4.  Telnet should h