Mail App and PHP version

I have got Nextcloud 11.0.2 installed in a shared hosting environment under Debian Jessie. Now I want to activate the Mail App and find that my PHP version (7.1.3) is too “young”. In the systems requirements section or the System Admin document a requirement of PHP 7.0+ is mentioned. When might Mail work with PHP 7.1.3?
Thanks for any help

My test system is at version 11.0.1. In THAT version Mail functions (more or less!) like it should!