cd /tmp
wget https://github.com/php/php-src/archive/php-7.2.34.zip
unzip php-7.2.34.zip
cd php-7.2.34/ext/
sudo apt install libc-client2007e-dev
sudo apt install libkrb5-dev
phpize7.2
./configure –with-kerberos -with-imap-ssl
echo ‘extension=imap.so’ > /etc/php/7.2/mods-available/imap.ini