When I switched to PHP 7.4 I forgot to specify sendmail_path parameter in php.ini and my contact form stopped working. Today I found sendmail_path parameter in PHP 7.0:
cd /etc/php
find . -name "php.ini"
./7.0/fpm/php.ini
./7.0/cgi/php.ini
./7.0/cli/php.ini
./7.4/fpm/php.ini
./7.4/cli/php.ini
grep sendmail ./7.0/fpm/php.ini
sendmail_path = "/usr/sbin/sendmail -t -f *****@yandex.ru -i"
And added it to PHP 7.4:
sudo nano ./7.4/fpm/php.ini
sudo service php7.4-fpm reload
and my contact form started to work.
Also I noticed that the certificate from smtp.yandex.ru changed:
openssl s_client -starttls smtp -crlf -connect smtp.yandex.ru:25
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----
but the old one still works.
Started to get:
SASL authentication failed; server smtp.yandex.com[2a02:6b8::19d] said: 535 5.7.8 Error: authentication failed: Invalid user or password!in
/var/log/mail.logand updated the password:
cd /etc/postfix/private/nano sasl_passwd
postmap sasl_passwd
service postfix restart