I have paid version and...

This is very, very important function.
Schedule or monitoring function will be great too.

This is the mail system at host pl.mediahuman.com.

I'm sorry to have to inform you that your message could not
be delivered to one or more recipients. It's attached below.

For further assistance, please send mail to postmaster.

If you do so, please include this problem report. You can
delete your own text from the attached returned message.

The mail system

<[email protected]>: host gmail-smtp-in.l.google.com[142.250.102.27]
said: 550-5.1.1 The email account that you tried to reach does not exist.
Please try 550-5.1.1 double-checking the recipient's email address for
typos or 550-5.1.1 unnecessary spaces. For more information, go to 550
5.1.1 https://support.google.com/mail/?p=NoSuchUser
4fb4d7f45d1cf-5edc168753dsi4319042a12.80 - gsmtp (in reply to RCPT TO
command)

Статус доставки

Reporting-MTA: dns; pl.mediahuman.com
X-Postfix-Queue-ID: E49A03E1223
X-Postfix-Sender: rfc822; [email protected]
Arrival-Date: Sun, 30 Mar 2025 21:31:27 +0200 (CEST)

Final-Recipient: rfc822; [email protected]
Original-Recipient: rfc822;[email protected]
Action: failed
Status: 5.1.1
Remote-MTA: dns; gmail-smtp-in.l.google.com
Diagnostic-Code: smtp; 550-5.1.1 The email account that you tried to reach does
not exist. Please try 550-5.1.1 double-checking the recipient's email
address for typos or 550-5.1.1 unnecessary spaces. For more information, go
to 550 5.1.1 https://support.google.com/mail/?p=NoSuchUser
4fb4d7f45d1cf-5edc168753dsi4319042a12.80 - gsmtp