https://muff.kiev.ua/content/exim-nastroika-avtootvetchika

vi /etc/exim4/exim4.conf

#ROUTERS CONFIGURATION
begin routers
...
autoreply:
    driver = accept
    retry_use_local_part
    no_expn
    no_verify
    unseen
    condition = ${lookup mysql{SELECT login FROM users \
		WHERE login='${local_part}' \
                AND domain='${domain}' \
                AND reply = '1'}{yes}{no}}

    #####senders = ! ^postmaster@.*:\
    #####          ! ^root@.*:\
    #####          ! ^noreply@.*
    
    condition =  ${if eq{${lookup mysql \
                {SELECT domain FROM users \
                WHERE login='$sender_address_local_part' \
                AND domain='$sender_address_domain'}}} \
                {$sender_address_domain}{yes}{no}}

    condition =  ${if eq{${lookup mysql \
                {SELECT login FROM users \
                WHERE login='$sender_address_local_part' \
                AND domain='$sender_address_domain'}}}\
                {$local_part}{no}{yes}}

    transport = address_autoreply
...

#TRANSPORTS CONFIGURATION
begin transports
...
address_autoreply:
	driver = autoreply
	text = ${lookup mysql{SELECT text_reply FROM users WHERE \
		login='${local_part}' AND domain='${domain}'}}
		from = $local_part@$domain
	once_repeat = 1d
	subject = "Autoreply from $local_part@$domain"
	headers = "Content-Type: text/plain; charset=utf-8"
	to = $sender_address
...

mysql -uroot -p

USE exim;
ALTER TABLE users ADD reply ENUM('0',  '1') NOT NULL DEFAULT  '0';
ALTER TABLE users ADD text_reply TEXT;