Issue after installing PHP 7.4

Then you must did something wrong while following the guide. WordPress link. sending emails from Wordpress works perfectly with this, I use it on several servers.

There are no edits in postfix config required besides of what's described in the perfect server tutorial. Follow it to the letter and you are ready to go.

post thepostfix master.cf file and the messages that you get in mail.log when sending an email.

That's ok and can be ignored.

 

There you have the reasons for your issues, compare your master.cf with the guide, then you will see the mistakes you made:

1) You missed removing # in front of the submission line.
2) You missed removing # in front of the smtps line.
3) You twice added the code ^M which should not be there.

 

I suggested to use the official installation instructions for the reinstall plus I suggested to compare your setup after it failed with the official installation instructions, which you apparently have not done.

For Apache: https://www.howtoforge.com/tutorial...l-pureftpd-bind-postfix-doveot-and-ispconfig/
For Nginx: https://www.howtoforge.com/tutorial/perfect-server-ubuntu-18-04-nginx-bind-dovecot-and-ispconfig-3/

The script you used is a third party script and not from ISPConfig, I can't say if it will install ISPConfig correctly.

 

There are several issues, first, you used a wrong hostname. the server hostname must be a subdomain as shown in perfect server tutorials, but you used a full domain which makes that domain unusable for email.

Change:

nushara.com

to:

server.nushara.com

in the files:

/etc/hostname
/etc/mailname/
/etc/postfix/main.cf
/etc/hosts

and then reboot the server. In addition to that, you must create a dns a-record in the dns server that is responsible for that domain plus you have to set a reverse record for the IPv4 and IPv6 address of the server that point to server.nushara.com.

 

Then there must be a different error in the /var/log/mail.log from what you posted until now. Send an email with Wordpress and post ALL lines that got added for that in the mail.log file.

 

As far as I can see, WordPress did not attempt to send an email. Check the settings in Wordpress, Wordpress should either use the PHP mail function or make an SMTP connect to localhost (which is IP 127.0.0.1)