nginx.autodiscover.example.conf

    location ~ /(?:a|A)utodiscover/(?:a|A)utodiscover.xml {
        root /var/www/;
        try_files /autodiscover/autodiscover.php =404;
        fastcgi_pass unix:/run/php-fpm/php-fpm.sock;
        fastcgi_index  index.php;
        include        fastcgi.conf;
        fastcgi_param SERVER_ADDR "";
        fastcgi_param REMOTE_ADDR $http_x_real_ip;
    }

／var／www／autodiscover／autodiscover.php

<?php
//get raw POST data so we can extract the email address
$data = file_get_contents("php://input");
preg_match("/\<EMailAddress\>(.*?)\<\/EMailAddress\>/", $data, $matches);

//set Content-Type
header("Content-Type: application/xml");
?>
<?php echo '<?xml version="1.0" encoding="utf-8" ?>'; ?>

<Autodiscover xmlns="http://schemas.microsoft.com/exchange/autodiscover/responseschema/2006">
    <Response xmlns="http://schemas.microsoft.com/exchange/autodiscover/outlook/responseschema/2006a">
        <Account>
            <AccountType>email</AccountType>
            <Action>settings</Action>
            <Protocol>
                <Type>IMAP</Type>
                <Server>imap.yandex.com</Server>
                <Port>993</Port>
                <DomainRequired>off</DomainRequired>
                <LoginName><?php echo $matches[1]; ?></LoginName>
                <SPA>off</SPA>
                <SSL>on</SSL>
                <AuthRequired>on</AuthRequired>
            </Protocol>
            <Protocol>
                <Type>POP3</Type>
                <Server>pop3.yandex.com</Server>
                <Port>995</Port>
                <DomainRequired>off</DomainRequired>
                <LoginName><?php echo $matches[1]; ?></LoginName>
                <SPA>off</SPA>
                <SSL>on</SSL>
                <AuthRequired>on</AuthRequired>
            </Protocol> 
            <Protocol>
                <Type>SMTP</Type>
                <Server>smtp.yandex.com</Server>
                <Port>465</Port>
                <DomainRequired>off</DomainRequired>
                <LoginName><?php echo $matches[1]; ?></LoginName>
                <SPA>off</SPA>
                <Encryption>TLS</Encryption>
                <AuthRequired>on</AuthRequired>
                <UsePOPAuth>off</UsePOPAuth>
                <SMTPLast>off</SMTPLast>
            </Protocol>
        </Account>
    </Response>
</Autodiscover>

／var／www／autodiscover／config-v1.1.xml

<?xml version="1.0" encoding="UTF-8"?>

<clientConfig version="1.1">
    <emailProvider id="domain.tld">
        <domain>domain.tld</domain>
        <displayName>Mail</displayName>
        <displayShortName>Mail</displayShortName>
        <incomingServer type="pop3">
            <hostname>mailserver.domain.tld</hostname>
            <port>995</port>
            <socketType>SSL</socketType>
            <authentication>password-cleartext</authentication>
            <username>%EMAILADDRESS%</username>
            <pop3>
                <leaveMessagesOnServer>true</leaveMessagesOnServer>
                <downloadOnBiff>true</downloadOnBiff>
                <daysToLeaveMessagesOnServer>10</daysToLeaveMessagesOnServer>
            </pop3>
        </incomingServer>
        <incomingServer type="imap">
            <hostname>mailserver.domain.tld</hostname>
            <port>993</port>
            <socketType>SSL</socketType>
            <authentication>password-cleartext</authentication>
            <username>%EMAILADDRESS%</username>
        </incomingServer>
        <outgoingServer type="smtp">
            <hostname>mailserver.domain.tld</hostname>
            <port>587</port>
            <socketType>STARTTLS</socketType>
            <authentication>password-cleartext</authentication>
            <username>%EMAILADDRESS%</username>
        </outgoingServer>
    </emailProvider>
</clientConfig>

Is there more documentation for this / other possible config options?

See this: https://github.com/gronke/email-autodiscover/blob/master/mail/autodiscover.xml