by default, the IMAP for PHP is deactivated. First, you need to check whether PHP IMAP is installed or not. lets check with phpinfo() function.
Check PHP IMAP Is Install.
1) Create a new file in your root directory called “whatever.php” and put below small code on this file.
Note: it is not a good practice to name the file “phpinfo.php”, because some attackers search for files with that name on your servers. so, please keep it in your mind.
2) Now, run this file from your favorite browser.
3) You can check the same as snap below.